FORGET last week - or at least, treat it as little more than a prelude to tonight's action.

Gregor Townsend is convinced that no matter how well his Glasgow side played for stretches of their 32-10 win over Ulster six days ago, they will need to improve by a considerable margin if they are to get the better of the same opponents in this evening's PRO12 play-off semi-final at Scotstoun.

The principal reason for that, of course, is that those opponents are not really the same at all. Only four Ulster starters remain from last week and such formidable foes as Rory Best, Ruan Pienaar and Tommy Bowe are back in the line-up from kick-off.

"We'll need to play 10 to 20% above what we've done already this season," Townsend, the Warriors' head coach, said yesterday after naming a team in which there are only two changes of personnel from the league match. "That starts in the last 10 minutes of each half. When you're feeling tired, you keep working hard.

"That's when we need the crowd behind us and the support of our team-mates to push us through. We'll require our best performance to make it into another final.

"It's 80 minutes playing against a similar team, in that the opposition are Ulster. But [it is] a different group of players and we know it'll be a much better team than the one we played last week."

Last time round Glasgow went in search of - and got - the bonus point that guaranteed them a home semi-final. Townsend explained his team's approach will not be that different tonight, even though any kind of win will take them through to next weekend's final in Belfast.

"It was never really something we discussed until half-time, about the bonus point, last week," he said. "All we were looking to do was win the game and that's what we're looking to do this week.

"You have to get all the elements in place to beat a team such as Ulster. We have to show a patience, but a relentless patience. We have to be knocking on the door to get those opportunities.

"And defensively we have to make sure that we produce our best performance. We're up against some real quality players, so low tackling, line speed, discipline in defence will be key.

"We prepared to play against these players last week. It wasn't until 24 hours before kick-off that we realised they weren't going to play and we went to look at different players. But it [Glasgow's strategy] is built on what we were planning to do last week and we know it's the quality of playing an international team when you have those guys against you. And we have to take them out of the game.

"We probably played to the conditions too much last week. We knew the wind was going to be a big advantage and it was really the last half an hour before we stepped it up. So I believe this week we have to impose our game no matter what the conditions."

A few seasons back, even the Warriors' staunchest supporters might have lacked faith in their team's ability to impose themselves no matter what, but the squad has now accrued far more experience of prevailing in big matches. While Ulster appear certain that their big guns will power them into the final at their own Kingspan Stadium, Townsend is equally sure that his players have the resilience to carry the day.

"I think the expectation within this group of players and the supporters is that we have a group of players to get to another final. Our strongest team, we feel, will be able to take on Ulster.

"We've played in semi-finals and the final. The experience of playing these big games, our players now have that, but you can't predict the future - you have to win the game that is in front you. You have to make that tackle, take that opportunity. But I'm certainly very excited to see our players go up against Ulster."

As Heineken Cup winners all the way back in 1999, and victors in the Celtic League in 2006, Ulster have done a lot more in decades past than merely get to finals. But that Celtic League title was their last trophy to date, and the current side has only a handful of survivors in it.

"The teams we've had over the years, it's disappointing to think that's the last time we won a trophy," Bowe, one of those survivors, said. "Knowing the final is at the Kingspan is a great carrot for us.

"It's amazing to think there hasn't been an away win in the play-offs in recent years. We'd love to create that little bit of history and go on and win the final at home."

Glasgow, of course, have an alternative history in mind.