The reigning champions were well on top but unable to make their superiority count and, on 24 minutes, they were hit with a sucker-punch.

A mix-up in the Munster midfield, the ball went to deck and Steyn was first to react to gather and sprint away to score under the posts.

Simon Zebo looked to hit back for the Irish side but was bundled into touch by Huw Jones as he bore down on the try-line.

Warriors would keep their four-point lead intact until the break, but not before losing Matt Fagerson to a yellow card for a high tackle on Peter OMahony.

The 14 men started the second half on the front foot and passed up two kickable penalties to go to the corner, only to be repelled on each occasion by the Munster defence.

When Glasgow were given another penalty within range, Horne pulled his effort wide.

Then came a moment of pure quality. Tom Jordan fielded a 22 restart deep in his own territory, ran it back and linked up with Rory Darge. He found Jones, who scorched earth through the Munster midfield and fed Cancelliere, who evaded the cover defence to touch down.

Horne made his adjustments and banged over a superb conversion to give Glasgow a 14-3 lead.

Darge was required on the other side of the ball when a brilliant turnover near his own line foiled Munster momentum that looked certain to lead to a try.

The home side did not have long to wait, however. Horne's charged-down box-kick handed possession to Munster and, after a few phases, prop Jeremy Loughman burst free and eventually the ball was worked wide to Frisch to score.

Glasgow again did well to weather the storm and Munster finished the game with 14 men after Nankivell's reckless clearout made contact with Horne's head.

The scrum-half got up to nudge over the penalty to stretch his side's lead to seven.

Munster could not conjure a late rescue act and it will be Glasgow who travel to South Africa for the final, aiming for a first title in nine years.