DTH van der Merwe grabbed the Glasgow try

Big money South African recruit Ruan Pienaar scored all Ulster's 19 points. The Springbok scrum-half, on his debut, crossed for a try, which he converted, in addition to landing four penalties, to see the Ravenhill side home in a game which saw the lead change hands several times.

The outcome was in the balance right up until the final whistle which consigned the Warriors to their fourth straight defeat.

After Pienaar failed with an early penalty attempt from inside his own half, the Warriors took control of the game with two rapid scores arriving in the ninth and 10th minutes.

Firstly Duncan Weir slotted a penalty after Bryan Young was penalised in the tackle zone, and then DTH Van der Merwe got on the end of a pass from Max Evans and made the left corner after Andrew Trimble spilled a high ball just inside his own half.

Weir failed to add the extras and Ulster narrowed the margin with Pienaar's first points for the province when the Springbok saw his penalty come in off the left upright after Glasgow were penalised at a scrum. he soon added another penalty.

Ulster's new signing got on the scoresheet again when, in the 23rd minute, Ulster drove a lineout near the Warriors' line and Rory Best, on his 100th appearance, peeled off on the blind side and put Pienaar in at the right corner.

The odds were against the South African converting his own score, but he nailed it with a perfect kick to give Ulster a 13-8 lead.

Two minutes later, Weir's second penalty narrowed Ulster's lead to two points and then, after Dan Tuohy was penalised for taking out Van der Merwe, Glasgow launched an attack on Ulster's line that led to another Weir penalty which put the Warriors ahead by a point at half-time.

Pienaar put Ulster back in the lead with a 44th-minute penalty which bounced in off the crossbar, but that was cancelled out five minutes later by Weir who put the Warriors back in front.

Glasgow number eight Richie Vernon was then curiously not shown the yellow card after he took Trimble out - though both the Ulster winger and Paddy Wallace appeared to have knocked on in a rare Ulster attack - and from the resulting penalty Pienaar wastefully put the kick wide.

Weir fired wide with a 65-metre effort and then, with Ulster turning the screw, Pienaar kicked a fourth successful penalty to put Ulster 19-17 in front.

He sent another straightforward-looking kick against the upright, and this time it stayed out, making for a tense finale, but Ulster clung on for four points.