These are the facts: We know the match took place on January 10, 2000, on court six at the Auckland Tennis Centre on Stanley Street. It was the opening day of the Heineken Open.
We don't know how long the match lasted, how many people watched, or even the identity of the chair umpire. Among the little we do know is that it finished 6-4 6-4 and the court may have smelt like sewage.
Eighteen-year-old seventh seed Juan Carlos Ferrero was up against a fellow teen, and an unknown number of minutes later, his opponent walked off the side court furthest from centre court. He has never returned here to play. New Zealand remains the only country where Roger Federer has never won a set, let alone a match.
Since the 2000 Heineken Open, Federer has amassed 88 career titles, including a record 17 grand slams, and US$97 million in prizemoney. Before this match 16 years ago, he'd earned US$253,094.
The Federer-Ferrero side court encounter is one of the great sporting contests no one saw - not in the sense that it was an amazing match (maybe it was but tracking down anyone who could verify that was difficult) but that the two participants would go on to reach world No 1 within four years.
Here they were, playing in little, old Auckland and hardly anyone saw it, although no doubt many claim they were there.
It is a match that has grown in significance since the legend of Federer developed. Did he pull off his first tweener? Did it feature one of the infamous tantrums Federer was known for early in his career?
Heading into the match, Ferrero was world No 43 and had just won Newcomer of the Year. Federer was ranked 61, the youngest in the world's top 100. Eighteen months earlier, he was 878th. Both players were aged 18 and at the start of their third year as professionals.
Federer has now played 1300 matches on the ATP tour. This was his 36th. Going into the match, he'd won just 15, with a victory over world No 5 Carlos Moya the highlight.
There is very little on record of the match. A hunt in the Herald archives found it didn't warrant a mention in the paper, even in the results section.
Tennis reporter Terry Maddaford focused his lead story on the main centre court opening-round clash between former world No 2 Michael Chang and Zimbabwe's Byron Black. Former New Zealand No 1 Mark Nielsen also had time on centre court that day during his 6-4 6-4 defeat to Sweden's Magnus Gustafsson.
Among others in the main draw were top seed Tommy Haas, the second seed and eventual champion Magnus Norman, Jiri Novak, Goran Ivanisevic, Jonas Bjorkman, Gaston Gaudio, Sjeng Schalken and Nicolas Escude.
Chang was unseeded but was an invited player and made the final, going down in three sets to Norman. A side-court clash between two no-names was well off most people's radar.
"I watched most of Chang's game because that was the first time he'd been to New Zealand and there was quite a bit of interest in him," Maddaford recalls.
"On the first day of the tournament, there are a lot of games and there is probably only going to be four or five on centre court at the most. You are basically watching the games there because the organisers try to get the best on centre court because that's where the crowd is.
"An unseeded young player playing the seventh seed, not a particularly enthralling game. How would you know that R Federer from Switzerland was going to go on and do anything at that stage?
"You could fluke it and watch a game like that but you'd have to have some reason for it. And there would be no real reason to go and watch an 18-year-old Swiss player playing the seventh seed when you can watch Michael Chang on centre court at the same time."
Tournament director Graham Pearce also missed seeing Federer in action but for different reasons.
"I didn't watch the match because there was a lot of other stuff going on at the same time," Pearce says. "It's amazing - you don't get to sit and watch many matches, actually, when you are running a tournament."
There is little intrigue about how Federer came to play in Auckland. Pearce had no inkling Federer would become a superstar of the game, so didn't chase him.
Federer would have been like most other players and alerted event organisers that, due to his world ranking, he'd like to enter the main draw.
"We encourage up-and-comers and, to my knowledge, he entered the tournament because his ranking was high enough to get in on his own accord," Pearce says.
"We certainly wouldn't have been discouraging him as an up-and-comer. And it would have been the same for Juan Carlos.
"Whenever we talked to Roger about coming back, he always said, 'well, you put me on court six last time'. I always responded, 'well, you got beaten. If you come back, we'd put you on centre court'."
Herald reader Greg Lim says he attended the match with his mother and that the crowd figure was about five, which means they were well out-numbered by the ball boys and linespeople working the match.
Lim says he was attracted to the match because Federer was a recent junior world number one and was surprised more people weren't interested in the clash. He says Federer wore a surfer beads necklace and may have had a short tied pony-tail.
"I was more impressed with Juan-Carlos' play that day, and nothing suggested to me Federer was to go onto great heights," he emailed the Herald.
Dave Worsley, the tournament's media manager at the time, remembers it differently and says he tried his best to alert people of a possible must-see clash.
He told host broadcaster TVNZ to get a camera down for the match, as it was expected to be a good contest between two promising young players.
"I said, 'watch out for this guy Federer, if he can control his temper, he's really good'."
Unfortunately, no one listened. It was an era before Twitter, Instagram, YouTube and Facebook and the Herald website was less than a year old. There is very little record of the match.
There is footage on YouTube of Ferrero's quarter-final defeat to compatriot Joan Balcells a few days later (posted by Balcells himself).
But, according to Worsley, the crowd grew as word got out of a decent contest.
"I remember the crowd built up as people thought, 'holy s***, this is a good match'.
Anyone with half a tennis brain would think, 'wow, these guys are good'."
Worsley caught part of the match on a court that had its quirks. Court six barely met the restrictions for the space permitted around its perimeter, with a brick wall down one side. There was also a sewerage shed that every now and then would emit a stink across the arena.
"The great thing about court six was that you pretty much ran into a wall," Worsley remembers. "There were oak trees right against the court and the leaves would fall on to the court. It was the correct length but the sides were just within the restrictions. Fans could hang their legs on to the court and look down on the players.
"It was a really lovely scene with the oak trees and closeness to players duelling. But it stank. I can't remember if it did that day but it was possibly a stinky match."
Christine McKnight was a line judge for the match.
"It was like watching two high school kids play," she remembers. "They were so young and nobody really knew who they were. The thing that stuck with me was that they were both darn good players and it was a couple of years later that they became big names and I thought, 'Oh, wow, I've actually been on court with them'."
Ferrero told the Herald he remembers the clash but was vague on detail. It's easy to understand why given it was 16 years ago and just one match of the 741 he played in his 14-year career.
"I remember all my matches with Roger Federer," Ferrero says. "When I was younger, I had to play doubles against him, but that match in Auckland was the first time that we had played each other in an individual match.
"He was a young player that was already showing his talent, but a little bit more distracted and unfocused . . . more irregular.
"It's always great to have had the possibility to play such a large number of matches with the best player [in tennis history].
"In general, I have got really nice memories of Auckland. It is a really pleasant tournament, run in a wonderful city."
Worsley said, even then, he could tell Federer and Ferrero were two talented players who had big futures ahead of them.
"You could see Federer was a frustrated genius but knew he could do better," Worsley says. "You saw frustration but also talent. People were talking about his one-handed backhand, as a lot of players were going with two back then. Ferrero was just a whippet."
The next time the pair met was at the slightly more glamorous surroundings of Flushing Meadows in the third round of the US Open.
Ferrero triumphed again, winning 7-5 7-6 1-6 7-6 and handing Federer his first defeat in New York. Ferrero was knocked out by eventual champion Marat Safin in the next round.
Understandably, Ferrero has clearer memories of their US Open meeting.
"I remember that the match was stopped because of rain. It happened when Federer was serving. I had a break point in that exact moment so, while we were waiting, I remember talking with my coach in the locker room about where we guess he will serve. Finally, I won the match in four sets. It was a really hard match."
Federer would win the first of his five straight titles there three years later. By the end of the year, Federer was ranked 28th in the world and becoming too big a drawcard for the Heineken Open. Ferrero returned to Auckland in 2005 and became a regular, making the final in 2008.
Overall, they met 14 times, twice at Wimbledon and once at the Australian Open, with Federer winning their final 12 encounters. But it all started in Auckland.
"I remember playing [in Auckland] once," Federer told the Herald on Sunday in 2010, when asked if he wanted to return one day. "I think it was also the time when [the] America's Cup was held there. I didn't win a whole lot of matches.
"I played on the outside court and lost first round to [Juan Carlos] Ferrero. Right now, obviously the Middle East swing for me works very nice.
"But you never know in the future. I might always switch around my schedule. You never know. I'd like to come back."
That was six years ago and nothing has changed. Federer played the Brisbane International this week ahead of his 16th consecutive Australian Open.
He's not coming back, especially to court six which, during the 2011 redevelopment of the ASB Tennis Centre, was turned into a carpark.
Court six is now just a distant memory, which is probably where Federer has forever consigned his one match in New Zealand.
Correction: An earlier version of this story stated that Roger Federer has won 18 grand slams. He has in fact won 17.