Glasgow teed-up an intriguing RaboDirect PRO12 run in as they edged out leaders Ulster 20-14 at Scotstoun to slash their advantage at the top of the table to just four points.
Gregor Townsend's men 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 who could only manage three successful penalties from Ruan Pienaar and Stuart Olding's second-half touchdown.
The victory thrilled a capacity 5,600-strong crowd that included Rangers manager Ally McCoist, but there were worried looks as the hosts' South African wing DTH van der Merwe was stretchered off wearing a neck brace and oxygen mask eight minutes into second half following a clash of heads.
Thankfully the early prognosis from Glasgow's medics was positive and his immediate withdrawal had only been precautionary.
Edinburgh centre Nick De Luca was sent off for a dangerous tip tackle on Tom Grabham as the Ospreys secured a comfortable 24-7 victory at the Liberty Stadium.
De Luca saw red four minutes from time to add misery to the Scots as they slipped to their 10th straight defeat in all competitions.
Two tries from No 8 and man of the match Morgan Allen and one from scrum-half Rhys Webb were enough to see the Ospreys home. The Edinburgh try came from flanker Hamish Watson.
Connacht claimed their first-ever RaboDirect Pro 12 away victory over the Blues, with lively flanker Willie Faloon contributing two tries in a 26-22 win.
The only occasion Connacht had previously managed a win in the Welsh capital was in the pre-regional era, when current coach Eric Elwood kicked them to a 6-3 success over the Cardiff club side in 2001.