David Humphreys maintained Ulster's push for the Celtic League title as he kicked five penalties in a 27-18 defeat of Glasgow Warriors at Firhill.
CELTIC LEAGUE: Saturday, April 15
GLASGOW WARRIORS 18 ULSTER 27, Firhill (Att: 2,240)
Scorers: Glasgow: Tries: Hefin O'Hare, John Beattie; Con: Dan Parks; Pens: Parks 2
Ulster: Tries: Isaac Boss, Justin Harrison; Con: David Humphreys; Pens: Humphreys 5
Humphreys kicked 17 points in all with tries from scrum half Isaac Boss, who had another encouraging game, and former Wallaby lock Justin Harrison securing a sixth League win in a row.
Mark McCall's side are now three points behind League leaders Leinster, with a game in hand. The men in white continued their impressive away record in the competition on Saturday - they have now gained 25 League points on their travels this season.
Ulster came flying out the blocks at Firhill and were on the board with less than a minute on the clock.
Boss sent a testing chip into the hosts' 22 that was eventually collected by Rory Lamont but his team-mates were penalised for entering the ruck illegally from the side. Humphreys opened the scoring with the resultant penalty but Glasgow almost replied with a try soon after but centre Andy Henderson's pass to his midfield partner Hefin O'Hare was ruled as forward.
20 minutes in, Ulster grabbed the game's first try. Glasgow winger Colin Shaw was penalised for an early tackle from which Ulster surged into the 22 - Boss produced a smart dummy before touching down. It was the former Wellington Hurricane's second try in four League games.
Humphreys converted but Glasgow responed with a penalty from the boot of out-half Dan Parks that was set up by a powerful burst by Henderson.
Then Humphreys thumped over a long-range penalty after Warriors hooker Scott Lawson was warned for dissent. 13-3 down, things got worse for the home side when Harrison grabbed Ulster's second touchdown, two minutes before the break.
Into the second half, Humphreys slotted another penalty before the Scots rallied with a try from replacement flanker John Beattie.
Parks traded penalties with Humphreys on 58 and 62 minutes before Beattie set up another score for O'Hare that Parks converted, ensuring a tense finale with Ulster's lead cut to 24-18.
However any hope of a late comeback were denied when Humphreys slotted over his fifth and final penalty to push his League tally for the season to 179 points.
TIME LINE: 2 minutes - Ulster penalty: David Humphreys - 0-3; 20 mins - Ulster try: Isaac Boss - 0-8; conversion: David Humphreys - 0-10; 30 mins - Glasgow penalty: Dan Parks - 3-10; 34 mins - Ulster penalty: David Humphreys - 3-13; 38 mins - Ulster try: Justin Harrison - 3-18; conversion: missed by David Humphreys; Half-time - Glasgow 3 Ulster 18; 46 mins - Ulster penalty: David Humphreys - 3-21; 52 mins - Glasgow try: John Beattie - 8-21; conversion: missed by Dan Parks - 8-21; 58 mins - Ulster penalty: David Humphreys - 8-24; 62 mins - Glasgow penalty: Dan Parks - 11-24; 66 mins - Glasgow try: Hefin O'Hare - 16-24; conversion: Dan Parks - 18-24; 69 mins - Ulster penalty: David Humphreys - 18-27; Full-time - Glasgow 18 Ulster 27
GLASGOW: Graydon Staniforth; Rory Lamont, Hefin O'Hare, Andy Henderson, Colin Shaw; Dan Parks, Sam Pinder; Kevin Tkachuk, Scott Lawson, Euan Murray, Dan Turner, Craig Hamilton, Andrew Wilson, Donnie Macfadyen, Jon Petrie (capt).
Replacements used: John Barclay for Wilson (38 mins), John Beattie for Macfadyen (40), Fergus Thomson for Lawson, Ben Prescott for Murray (both 59), James Eddie for Turner (63), Calvin Howarth for Pinder (80+3). Not used: Spencer Davey.
ULSTER: Bryn Cunningham; Tommy Bowe, Andrew Trimble, Jonathan Bell, Andrew Maxwell; David Humphreys, Isaac Boss; Bryan Young, Rory Best, Simon Best (capt), Justin Harrison, Matt McCullough, Neil Best, Stephen Ferris, Roger Wilson.
Replacements used: Neil McMillan for Ferris (68 mins), Justin Fitzpatrick for Young (69), James Topping for Maxwell (80+3). Not used: Nigel Brady, Ryan Caldwell, Kieran Campbell, Adam Larkin.
Referee: Tim Hayes (Wales)