James Barclay had a good chance to make it into a tit-for-tat affair after a cross from Jared Bloor in the 16th minute but his shot from inside the box whizzed past the right upright.
But soon after Peta parried a shot to deny Karori, Greatholder, who didn't look as agile as his young charges but was undeniably instrumental in injecting experience and stability in the engine room, also fired a shot from the top of the box outside the right upright in the 19th minute.
The Havelock North midfielders needed to take more one-touch passes to catch Karori on the back foot but, regrettably, some of them too often opted to dribble and cough up valuable possession.
Conversely the Karori midfield of co-skipper Leonardo Villa, William Stuart and former Thirsty Whale Hawke's Bay United bench player Facundo Barbero operated like a well-orchestrated drive-in operators at a fast-food chain.
Barbero, who should have left an impression on Bay United coach Brett Angell on the sideline, pushed the Wellingtonians 2-1 ahead in the 34th minute when it seemed as if the Wanderers' defence gave him too much time and space to unleash the ball past Peta.
The villagers were still recovering from the goal when Villa rocketed a pile driver from the top of the box but a defender kicked it away from the goal line amid gasps from the home fans on a day when rain stayed away during the game in wintry conditions.
Waterside Karori came back from the changing room in the second half with more urgency to execute a few raids.
That pressure saw Christensen collect a yellow card from referee Matthew Conger in the 54th minute for body checking a Karori play in full cry for a 50-50 ball after knowing he was going to come off second in the race.
Peta was left hollering at his defenders in the 61st minute after he tipped the ball over the top left-hand corner before Conger flashed a yellow card at Sam Waddington eight minutes later for tripping goalkeeper Martin from behind as he retreated from an uneventful attack.
Christensen had a golden chance to equalise in the 70th minute from a sitter about 5m of the left upright but his finish went begging on the wrong side of the post.
But what transpired in the 80th minute epitomised the frustration and ill-discipline that had crept into the hosts' game.
Christensen rightly collected his second yellow card and an early shower in the 80th minute for a mindless tackle on a player close to the visitors' bench when common sense suggested, especially as captain, he needed to stay out of trouble.
The Karori bench got on their feet to howl collectively at Conger to flash a remonstrating Christensen a red card. Greatholder, who was substituted minutes before, opened dialogue with the referee from the sideline to rebuttal the opposition's pleas.
However, Wanderers assistant coach Bruce Barclay yelled out at Conger to not let the Karori chorus influence his decision.
Conger delivered his red-card verdict and then took a couple of minutes to read the riot act to Greatholder to ask Barclay to immediately leave the Havelock North bench on the sideline. Christensen's input is over in the campaign.
The game got a little testy when a few minutes later Villa went down clutching his head and then hobbled off, prompting Garcia to ask a substitute to warm up as his replacement but the co-skipper returned to play until the final whistle.
Jackson Ralph again stood out for the Wanderers but, like other players, didn't put balls across when opportunities arose to create chaos in the Waterside Karori defensive box.
In the odd occasion when a ball was curled in, no one strayed deep in enough to become a nuisance in front of keeper Martin's prime real estate.
