Munster are bidding to reach their second successive Heineken Cup final, having lost to Leicester last year.
They avenged that defeat in the quarter-finals, while Toulouse eased past Northampton to book their berth in the last four.
80 min+: O'Gara tries another long-range drop goal but this time the ball drifts to the right of the posts, before the referee blows his whistle for full-time.
80 min+: O'Gara tries a long-range drop goal for Munster but the ball drifts just wide.
80 min: Munster are desperately chasing the game and have another five minutes of injury time in which to claw their way back into the lead.
72 min: Frederick Michalak goes over wide out after Toulouse attacked in waves and Jean-Baptiste Elissalde slots the conversion to take the hosts into the lead for the first time in the match.
Toulouse 13-12 Munster
64 min: Munster concede a penalty after some desperate defence and after Toulouse win the line out Xavier Garbajosa scythes over but fails to control the ball and Munster survive.
60 min: No sooner than they have got themselves back in the game Toulouse fall offside and O'Gara nudges Munster back into a six-point lead.Toulouse 6-12 Munster
55 min: Toulouse have come alive and, after Clement Poitrenaud is stopped just short, they kick a penalty to cut the gap to three.
Toulouse 6-9 Munster
54 min: Munster captain Jim Williams covers back brilliantly to just touch down a Toulouse kick ahead of the home attackers.
43 min: Munster extend their lead early in the second half as O'Gara clips over his second drop goal of the day.
Toulouse 3-9 Munster
40 min: Toulouse knock the ball on with the line at their mercy but they are then awarded an easy penalty and Delaigue slots it to get the home side on the board with the last kick of the half.
Toulouse 3-6 Munster
33 min: O'Gara pushes a fairly simple penalty wide to leave the visitors with a six-point lead.
28 min: Toulouse are awarded a penalty and kick it deep into the Munster 22 to force their first really threatening attacking position. Munster infringe again but Yann Delaigue pulls the kick wide.
Toulouse 0-6 Munster
17min: Toulouse kill the ball and O'Gara slots an easy penalty to extend the visitors' lead.
Toulouse 0-6 Munster
11min: Toulouse concede a penalty which Munster kick into the corner. The visitors win the lineout but cannot force their way through the Toulouse defence, and O'Gara is forced to drop a goal to open the scoring.
Toulouse 0-3 Munster
6 min: Ronan O'Gara hits the post with a penalty from just inside his own half.
1401 BST: Toulouse get the match underway in heavy rain that will make the ball very greasy.
Toulouse: C Poîtrenaud; E Ntamack, Y Jauzion, X Garbajosa, V Clerc; Y Delaigue, F Michalak; P Collazo, Y Bru, J-B Poux, D Gérard, F Pelous, J Bouilhou, T Brennan, C Labit.
Munster: J Staunton; J Kelly, M Mullins, R Henderson, A Horgan; R O'Gara, P Stringer; M Horan, F Sheahan, J Hayes, D O'Callaghan, P O'Connell, J Williams, A Quinlan, A Foley.
Referee: C White (England).