Glasgow teed-up an intriguing RaboDirect PRO12 run in as they edged out leaders Ulster 20-14 on Friday night at Scotstoun to slash their advantage at the top of the table to three points.
Yet they flirted with disaster as stand-off Peter Horne missed all five of his goal attempts, including an embarrassing conversion effort late in the second half while stationed dead centre and just 15 yards from the posts.
However, tries from Tim Swinson, Tommy Seymour, Peter Murchie and Nikola Matawalu were enough to hold off a determined Ulster side.
The victory thrilled a capacity 5,600-strong crowd that included Rangers manager Ally McCoist.
Ulster were first to trouble the scoreboard as South African scrum-half Pienaar made up for one ambitious 45-yard penalty miss by succeeding with another from a similar lengthy distance six minutes in.
Pienaar’s power with the boot was contrasted by Horne - making his 50th appearance for Warriors - who failed to even reach the goalposts with his tame first effort from just outside the Ulster 22.
It was a kick the fly-half should have managed with ease, but instead he would miss again as he failed to convert Swinson’s opening try on 13 minutes.
The score came as Glasgow worked quick ball from the left while the visitors found themselves hopelessly outnumbered on the opposite side. Centre Mark Bennett spotted the three-on-one imbalance and played in Swinson to swan dive over the line for his third score in two games after his double against Dragons.
The league leaders though failed to make much of their own ventures forward, first failing to cross over as Michael Allen was held up by Alex Dunbar and then later suffering a handling lapse as Andrew Trimble closed in on the whitewash.
Pienaar, however, did keep them ticking over in the meantime, putting over a second penalty to hand Ulster a 6-5 lead.
The scores remained as such until two minutes before the break when Warriors scrum-half Matawalu robbed Pienaar as he waited for the ball to emerge from a scrum and handed over to right wing Seymour for a simple finish. A third miss by Horne, though, kept the score at 10-6.
Pienaar finally missed with the boot as he erred from just 20 meters out, while the home side’s Pat MacArthur was held up at point-blank range right before the half-time break by some determined Ulster defending.
Just 31 seconds into the second period, however, they just about handed the hosts their third touchdown on a plate.
Full-back Murchie chased down Paddy Wallace’s kick five meters from his own try line and snaffled up the loose ball to extend Glasgow’s lead to nine points.
A fourth miss with the boot from Horne meant another unconverted try and Pienaar was able to add a third penalty of his own to bring the scores to 15-9.
Ulster thought they had then conjured their first try after 62 minutes when number eight Robbie Diack crossed over but Welsh referee Nigel Owens called it back for a forward pass.
But Mark Anscombe’s team were enjoying their most prolonged spell in Glasgow territory and finally found their way over the tryline on 67 minutes as Olding made the most of an overload down the right to score in the corner. Pienaar, though, missed for a second time with the conversion to leave the score at just 15-14 in the Scots’ favour.
Just as it looked set for a tense finish, however, Glasgow struck again as Matawalu collected a stunning offload by substitute Sean Kennedy just as he hit the deck to run in under the posts.