Glasgow Warriors returned to RaboDirect Pro12 action with victory over Ulster at Firhill.
Duncan Weir's three penalties to Ian Humphrey's one established a 9-3 half-time lead for the hosts.
Humphreys kicked Ulster level with two more penalties in the second half but the fly-half missed three other kicks on the night.
Troy Nathan's late try regained the lead for the Warriors and Weir's drop-goal denied Ulster a bonus point.
Glasgow's fifth successive league win, a sequence interrupted by a victory and a defeat in the Heineken Cup over the previous two weekends, puts Sean Lineen's men level on points with the division's joint-leaders, Ospreys and Leinster.
Ulster slip to eighth.
Graeme Morrison's kick into the corner put Ulster under pressure early on and the visitors eventually infringed, allowing Weir to kick the hosts ahead.
But the visitors began to impose themselves and Glasgow debutant David Lemi made an important tackle to prevent Simon Danielli making it to the line.
However, Glasgow were soon penalised and Humphreys kicked Ulster level.
The Warriors went back on the attack and two more penalties from Weir, the first awarded after a high tackle from hooker Andy Kyriacou on blood replacement Chris Fusaro, put them in command.
Humphreys had a chance to add to Ulster's tally before the break but his wayward kick sailed wide.
However, the fly half atoned for that miss at the start of the second half to bring Ulster back to within three points.
And Humphreys soon kicked Ulster level after Morrison was adjudged to have been in an offside position when gathering possession.
But Humphreys pulled his next two penalty attempts wide as Ulster missed the chance to move ahead.
And Glasgow took advantage with a sweeping move from right to left that ended with Troy Nathan and Lemi exchanging passes before the former went over in the corner.
Weir's conversion attempt was wide but a well-placed drop-goal from the fly half sealed victory.
Glasgow: Hogg, Lemi, Nathan, Morrison, Aramburu, Weir, Pyrgos, Welsh, MacArthur, Cusack, Ryder, Kellock, Harley, Barclay, Wilson.
Replacements: Cusiter for Pyrgos (53), Grant for Welsh (40), Low for Cusack (62), Gray for Ryder (62), Fusaro for Wilson (62). Not Used: Gillies, Dunbar, Shaw.
Ulster: D'Arcy, Trimble, Cave, Spence, Danielli, Humphreys, P. Marshall, Court, Kyriacou, Fitzpatrick, Muller, Tuohy, Diack, Faloon, Wannenburg.
Replacements: Whitten for Danielli (57), Brady for Kyriacou (70), Macklin for Fitzpatrick (63), Barker for Tuohy (70). Not Used: Black, McComish, Porter, Jackson.
Ref: Stefano Penne (Italy).