Wellington have defended their inaugural Capital Cup win 1-0 in an end-to-end encounter on Valentine's Day at Westpac Stadium.
On a night when the Video Assistant Referee (VAR) made their first live appearance in a match involving an A-League team, it was always likely the technology would have a prominent place in match headlines.
And despite positive attacking play from both sides, it was a pivotal moment in the 55th minute that proved decisive to the result, as referee Alan Milliner, after consultation with the video technology, awarded the home side a penalty.
Wellington Phoenix had started brightly and fashioned a gilt-edged opportunity just seven minutes in. Adam Parkhouse seized on a loose ball to run at the Beijing backline, feeding Roy Krishna, whose driven shot was saved by Beijing goalkeeper Dong Lei with his trailing leg.
From the resulting corner, first Hamish Watson and then Shane Smeltz went close in quick succession, with only a goal-line clearance from a BG defender preventing the latter from opening the scoring.
At the other end, Lewis Italiano made the most of his start, with Glen Moss rested, producing a terrific save to deny Chinese International Yan Xiangchuang from close quarters.
BG's playmaker Jin Hui earned the ire of referee Alan Milliner in the 17th minute, with a scything tackle from behind on Alex Rodriguez, after turning over possession.
Beijing's star Austrian striker Rubin Okotie had the first real chance for the visitors, but his chipped shot fell harmlessly onto the roof of the net, with Italiano standing tall.
In an end-to-end first half, Parkhouse was at the heart of many attacking moments and he thought he'd scored his first goal for the Phoenix in the 32nd minute, when he finished sharply from Roly Bonevacia's well-disguised through-ball.
It was flagged off by the linesman and referee Milliner was presumably happy with the ruling, as the Video Assistant Referees weren't called upon to offer an opinion.
There was no let-off in pace in the lead-up to halftime, as Hui found himself inadvertently blocking a team-mate's shot, before Parkhouse went close to poking home ahead of an on-rushing Lei.
At halftime, both sides elected to shuffle their packs, Phoenix making five substitutions and Beijing BG six.
After another lively opening, the VARs made their first appearance - and a profound one at that. Following an attacking corner for Wellington, referee Milliner called for assistance and after consulting the sideline video, adjudged a penalty against BG for a foul on Dylan Fox, as the cross came in.
Kosta Barbarouses, on at halftime, made no mistake from the spot, dispatching the penalty past Liu Tianxin.
Beijing BG continued to press, with halftime substitute Oliver Sail saving well in the Phoenix goal, before Okotie tried a 55m speculator, attempting to catch the young keeper off his line.
Youngsters Logan Rogerson, Liam Wood and young Academy graduate Calvin Harris entered the fray, as Wellington continued to play with tempo, but with silverware on the line, so did Beijing BG.
Both sides pushed for a goal, but for the second time in their two meetings, Wellington triumphed over their Sister City compatriots to the enjoyment of home fans.
Post-game, Wellington head coach Des Buckingham expressed his satisfaction that the Sister City Cup had doubled as more effective preparation for the crucial upcoming A-League clash against Melbourne City.
"It was a good runout, it was much better than a training session that we would have put on yesterday or today," said Buckingham. "There's nothing better than playing for the players and it's acted as good preparation for us for Melbourne."
"We were disappointed last week in the amount of possession we were able to keep, and be effective with; we kept a lot of possession tonight, and in good areas.
"It gave us a chance to look at two players upfront, in Hamish [Watson] and Shane [Smeltz] and I thought when we played through the middle, when we played them we looked quite dangerous."
Buckingham also praised younger players Sarpreet Singh, Rogerson and James McGarry, who enjoyed rare first-team appearances, but singled out a young Academy player for his contribution.
"The real pleasing thing for us was to bring Calvin Harris on, he's a sixteen-year-old Academy player ... he's a fantastic prospect and he's deserved his opportunity to be out there this evening."
On the VAR decision, Buckingham was circumspect, having not had an opportunity to view the vision post-game.
"We'll have a look at it and, as I said yesterday, if they've made the right decision - then that's what it's all about.
"I think if that's going to be the case in the league when they introduce it you're going to see a lot less shirt-pulling and a lot more goals from set plays as a result."