TALK about leaving it late.

Glasgow did not manage a try of any kind until 54 minutes into the game, but came good in the final quarter, not only to claim the four touchdowns they knew would earn a home Guinness PRO12 semi-final, but with the Ospreys failing to match them in Connacht, they ended the regular season top of the league.

Their reward is a return match against the same opponents on Friday night, with the winner heading to Belfast for the PRO12 final against the winner of the other semi, when Munster host the Ospreys at Thomond Park.

It will be a very different game, however - not only winner-takes- all, but Ulster will turn up in a totally different frame of mind and with a radically different team.

That said, Gregor Townsend, the Glasgow coach, can take a huge amount of confidence from the way his side finished this game, once Stuart Hogg had reminded everybody what an inspiration he can be with a dazzling solo try that lifted his side out of their mistake-ridden lethargy.

"All credit to Stuart Hogg for that try; it lifted the whole place and the players," said Townsend. "I loved his attitude when he was running back and saying 'let's get back down the other end and score again'. That was a turning point for me.

"The other was when they had a yellow card, we had them under pressure, had a number of scrums and Henry Pyrgos decided on a quick-tap penalty and we scored from it. That was great decision-making on the field."

What that did was change the game from Glasgow hoping to win, to Glasgow hunting the bonus point they desperately needed to make sure they stayed at Scotstoun for the semi-final. And in the end, it came with Finn Russell earning a 22-point haul and the man-of-the- match award, when he followed his first try in Glasgow colours with his second a few minutes later, setting the stage for Richie Vernon to get mobbed by his team-mates after scoring the fourth.

"I'm very, very proud of what they have achieved," said Townsend. "I had spoken before the game and told the players how proud the coaches were of them for being in the top two, so to actually finish first was an amazing achievement.

"We knew the conditions were not great, but to be 10-6 down after 50-odd minutes and come through like that shows the courage the players have, the courage to put their bodies on the line and go out and play ambitious rugby.

"We will need to look at things: we need to improve and there are different things we aim to show Ulster next week that we did not show in this game.

"At the end of the game, we were finding space because we had taken the confidence away from Ulster, but they had made 12 changes and will have some key players coming back, so we will need a similar performance to the one we gave against Munster at the same stage last year."

With Ulster having rested their leading players, after all-but giving up on a home tie themselves, what Glasgow desperately needed was a sprint start. They thought they had it, too, with the visitors mis-hitting the kick-off, Glasgow using the position to crash into the 22 and present Russell, the fly-half, with an early penalty to edge his side in front.

Hopes that that was the platform for a flood of points, however, were misplaced. With a strong wind behind them, Ulster were happy to play for territory and Glasgow were making far too many mistakes to do much about it.

The breakthrough came when Jonny Gray, the Glasgow lock, was sent to the sin-bin. Ulster took full advantage, going for line-out and drive that put Chris Henry, their captain, over for the opening try. Ian Humphreys converted and then exchanged penalties with Russell to leave the Irish four points ahead at the break, and good value for it, too.

The best Scots hope was that with the wind behind them, Glasgow could turn the screw, but there were few signs of them finding the essential killer instinct until Hogg took a hand in things with the kind of solo try that would light up any game.

There was nothing much on when he grabbed a pass that was probably not meant for him out of the air - only a hint of space, but that was enough. He fixed the last defender, chipped over him, rode the inevitable attempts to obstruct him, got to the ball first and outpaced the cover defence for a sparkling touchdown.

At last Glasgow woke up and started to show something of the form that had taken them top of the league, Russell selling a dummy and riding two half-hearted tackles to score under the posts and convert himself - amazingly, his first try for the club. With Ulster facing time down to 14 men, they pulverised the visitors' line. Pyrgos's brave decision to go for a tap penalty five yards out paid off as Russell again sold a dummy to score his second try.

Three down, one needed. The home faithful were on the edge of their seats - but not for long. The forwards hammered the Ulster line, until they released to the backs, where a perfectly timed short pass from Ryan Wilson to Vernon, his fellow centre, put the former back-row through for the fourth try.

The way he was mobbed by his team-mates showed they knew exactly what it meant, though they could not have realised the full significance until later, when word filtered through that they had not only claimed a home semi-final but had finished top in the league.

Glasgow Warriors: S Hogg (P Murchie, 73); T Seymour, R Vernon, P Horne (D Weir, 75), S Lamont (H Pyrgos, 51); F Russell, N Matawalu; R Grant (G Reid, 51), D Hall (P MacArthur, 51), R de Klerk (M Cusack, 51), J Gray (sin bin: 28-38), A Kellock (C) (L Nakarawa, 60), J Strauss, C Fusaro (R Wilson, 18-28, 51), A Ashe.

Ulster: L Ludik; R Scholes, S Arnold (R Pienaar, 73), S McCloskey (T Bowe, 63), M Allen (T Bowe, 10-20); I Humphreys (P Jackson, 49-55, 60), P Marshall: A Warwick (sin bin: 65-75), R Herring, R Lutton (B Ross, 60), L Stevenson, F van der Merwe (I Henderson, 19, R Wilson, 73), C Ross, C Henry (C) (I Henderson, 18-19, K McCall, 66-75), R Diack.

Referee: I Davies (Wales)

Attendance: 10,000