David Ferrer may have two more matches in the Heineken Open, but he likely faced his toughest test in last night's quarter-finals.
Few expected Guillermo Garcia-Lopez to cause the world No 3 too many problems - and for most of the first two sets that appeared true.
But, having already played the better tennis of the two Spaniards, Garcia-Lopez found another gear late in the second, seeing off Ferrer's attempts to serve out the match and sending it to a third set.
Ferrer eventually survived the scare to triumph 6-3, 5-7, 6-4, but the scoreline told only half the story in a match which left seasoned observers at Stanley St struggling to recall an encounter of a higher quality.
Garcia-Lopez may have lost five of their previous six encounters but the world No 58 matched his more illustrious compatriot for every blow, stroking some of the best backhands seen in recent years in Auckland.
He forced the unflappable Ferrer into uncharacteristic behaviour - repeatedly hitting unforced errors into the net, arguing calls and remonstrating with himself after missed shots.
That Ferrer still came out on top provided a vivid illustration of the class he brings to the event.
The four-time champion will head into today's semifinals having played three-set matches on back-to-back days, but he should still have too much quality for world No 62 Yen-Hsun Lu, who ended the fairy tale run of lucky loser Steve Johnson with a 6-4, 6-4 victory.
The main course served up by Ferrer and Garcia-Lopez came with a fitting entree, with John Isner and Philipp Kohlschreiber playing what was - for a couple of hours, at least - the match of the tournament.
If the rules of tennis made room for draws, the marathon match would have met every criterion.
In almost two-and-a-half hours, neither man managed to break the other's serve, with all three sets requiring tie-breaks to find a victor.
Isner came back from a set down to win both the second and third breakers, setting up a semifinal today against Roberto Bautista Agut. It could have been an all-American clash in the final four, but Bautista Agut dispatched Jack Sock earlier in the day. Isner, the third seed, will be confident of clinching a final spot, though the American's conditioning will receive a severe test following yesterday's exertions.
Fortunately for the 2.08m Isner, his type of game is hardly built on covering every inch of the court. The world No 14 showed his reliance on his not-so-secret weapon against Kohlschreiber, firing down 18 aces and winning a remarkable 83 per cent of points off his first serve.
"I served exceptionally well and that's the only reason I won," Isner said.
"Some days you're just in a good rhythm, and I was certainly in a good rhythm today."
The rhythm was clearly evident in Kohlschreiber bringing up only three break points across 18 games. Isner had just seven of his own, but managed the crucial mini-break to take out the final tie-break.
With each set lasting the distance, Isner was always going to hold the advantage, given he possesses the best tie-break record on the ATP.
And for Kohlschreiber, who reached the quarter-finals for the ninth time in 10 trips to Auckland, there was little to rue after a match devoid of opportunities. He had won his previous two matches against Isner but failed to manufacture many openings in his return game.
"It was one of those matches where I really didn't do anything wrong," he said. "It was very interesting and high-quality, but it was tough to be a loser."
Heineken Open - Day 5
Centre court - 3pm
1-Alexander Peya (AUT)/ Bruno Soares (BRA) v Daniele Bracciali (ITA)/ Lukas Dlouhy (CZE)
3 - John Isner (USA) v Roberto Bautista Agut (ESP)
1 - David Ferrer (ESP) v Yen-Hsun Lu (TPE)
Court 2 - 3pm
Eric Butorac (USA)/ Raven Klaasen (RSA) v 2-Julian Knowle (AUT)/ Marcelo Melo (BRA)