Munster have claimed a place in this year's Heineken Cup Final after a battling 25-17 victory over Castres in Beziers.

Fly-half Ronan O'Gara kicked 20 points from six penalties and a conversion, while wing John Kelly secured Munster's place in next month's Cardiff final at the Millennium Stadium by pouncing for an injury time try.

It means the perfect send off for coach Declan Kidney, who quits Munster to join Ireland's national set up at the end of this season, and veteran 36-year-old prop Peter Clohessy.

Munster, beaten by Northampton in the 2000 European Final, were made to work hard for their win in stamina-sapping conditions.

They trailed 9-0 five minutes before half time, but once O'Gara found his range, the Irish challengers moved sweetly through the gears.

Castres dominated large chunks of the game territorially, but they could never finish off the sterling efforts of their forwards, and only managed a consolation touchdown in the seventh minute of injury time from Scottish international wing Shaun Longstaff.

Castres were already down and out when Longstaff pounced, with Munster's red-shirted travelling army of 10,000 fans already celebrating.

Munster's triumph made amends for their agonising semi-final defeat against Stade Francais last season, and they can now look ahead to a May 25 appointment with either defending champions Leicester or Llanelli, who clash in tomorrow's second semi-final at Nottingham.

The game was never a classic - there was too much at stake for either side to be too adventurous - and in the end, O'Gara's goal-kicking proved the difference between two well-matched sides.

Castres made all the early running, and it looked as though it might not be Munster's day when their Irish international number eight Anthony Foley went off injured after just 16 minutes

Only three minutes later, both sides were temporarily reduced to 14 men when Clohessy, who had made a miraculous recovery from burns to his right arm to make the Munster starting line up, and rival prop Brent Moyle were sin-binned following an ungainly scrap.

Castres prospered from that situation, with fullback Romain Teulet kicking three penalties during a 15 minute spell when Munster were a distant second best.

Crucially though, Castres allowed their discipline to slip just before half time, and O'Gara landed two quickfire goals to make it 9-6 at half time.

Before the second period was a minute old, O'Gara had levelled the scores by completing his penalty hat-trick and Castres knew that all their hard work of the opening period was in danger of going to waste.

Munster could even afford to be without the influential O'Gara for seven minutes while he underwent treatment to a cut knee, but on his return, two further penalties during a seven minute spell meant that Munster had completed their fight-back at 15-9 ahead.

Castres, who had played with such expression and ambition in the first half, suddenly ran out of ideas, and although Teulet gave them hope through his fourth penalty strike, the closing stages belonged entirely to Munster.

Scottish star Townsend tried to rally his troops, yet it was all to no avail as another O'Gara penalty effectively put one Munster foot in the final.

Castres briefly threatened during the closing minutes, but when one of their ambitious attacking moves floundered, Kelly gathered loose possession to sprint unopposed and touchdown between the posts following a 30 metre dart.

O'Gara landed the simple conversion, and Munster were through to another Heineken Cup final, despite Longstaff having the final say when the men in red ran out of defensive numbers.

The Munster bandwagon will now roll into Cardiff, and their mere presence will guarantee a carnival occasion.

Whether it is Leicester or Llanelli who they meet, Munster have once again cracked the code for success in Europe.

Teams

Castres: Teulet, Mola, Artiguste, Berryman, Longstaff, Townsend, Albouy, Reggiardo, Ibanez, Moyle, I. Fernandez-Lobbe, Spanghero, Froment, Lassissi, Costes.

Not Used: R. Vigneaux, Dima, Chinaro, Bourdet, Sarramea, Delmotte, Plisson.

Tries: Longstaff.

Pens: Teulet 4.

Munster: Crotty, Kelly, Henderson, Holland, Horgan, O'Gara, Stringer, P. Clohessy, Sheahan, Hayes, Galwey, O'Connell, Quinlan, Wallace, Foley.

Not Used: Horan, Fogarty, M. O'Driscoll, O'Callaghan, Prendergast, Mullins, Staunton.

Tries: Kelly.

Cons: O'Gara.

Pens: O'Gara 6.

Att: 20,400

Ref: Chris White (England).