A try from Gavin Coombes two minutes from time gave Munster victory away to Castres, maintaining their 100% record in the 2021-22 Heineken Champions Cup.

They left it late but for the second time in six days proved they have the resolve when tough questions are asked.

After battling back with 14 men to defeat Ulster in the URC last Saturday, Johann van Graan's men again found themselves on the brink of defeat to Castres at Stade Pierre-Fabre.

The match was a scrappy affair, as the two sides who have met more than any other teams in the competition (18), played mostly to force errors from each other.

The ball was kicked from half to half with mistakes aplenty from the side receiving but in the end Munster had the last say.

A clever chip from Jack Crowley set up the field position and following a lineout and pressure close to the line, number 8 Coombes was on hand stretch over the line with one minute to play.

Munster remain second in Pool B after Harlequins secured a late win in Cardiff.

Nobody expected the game to be a free-flowing thriller and the teams duly delivered.

Played in freezing conditions and only after surviving a Covid-19 scare this morning, the match was hard on the eye for the most part.

The visitors took the lead in the 11th minute when Jack Crowley kicked a 40m penalty.

Tadhg Beirne and Peter O'Mahony were leading the charge as Munster disrupted Castres possession but the pack were wasteful when they infiltrated the opposition 22, losing a couple of lineouts in good position.

Castres, who had won their last three games in the Top14, grew into the game and scored the opening try in the 28th minute when Ben Botica chipped over the top for impressive full-back Thomas Larregain to touch down.

The out-half's conversion meant the hosts went in 7-3 ahead at the break.

The lively Mike Haley did his Ireland recall chances no harm and he allied with Keith Earls to break the Castres line, leading to another Crowley penalty seven minutes into the second half.

He repeated the trick three minutes later when Chris Farrell and Jack O’Donoghue made ground.

The game swung again and Botica landed two penalties after scrum pressure.

Munster, who had beaten Wasps away and Castres at home in the first two rounds, had 14 minutes to win it.

It looked as if they had blown their chance when they failed to secure a lineout in the home side’s 22.

But Beirne turned the ball over in Munster’s half and the two-time champions kept their cool to work the field position.

Coombes was most alert when the ball shot out of a ruck close to the line and his coverted try secured Munster’s passage to the knockout stage.

Castres: Thomas Larregain; Antoine Zeghdar, Thomas Combezou, Pierre Aguillon, Filipo Nakosi; Ben Botica, Santiago Arata Perrone; Antoine Tichit, Brice Humbert, Antoine Guillamon; Loic Jacquet (capt), Jack Whetton; Mateaki Kafatolu, Simon Meka, Baptiste Delaporte.

Replacements: Pierre Colonna, Julius Nostadt, Matthew Tierney, Ryno Pieterse, Hugo Hermet, Rory Kockott, Louis Le Brun, Bastien Guillemin.

Munster: Mike Haley; Andrew Conway, Chris Farrell, Rory Scannell, Keith Earls; Jack Crowley, Conor Murray; Dave Kilcoyne, Niall Scannell, Stephen Archer; Fineen Wycherley, Tadhg Beirne; Peter O'Mahony (capt), Jack O'Donoghue, Gavin Coombes.

Replacements: Diarmuid Barron, Jeremy Loughman, John Ryan, Jean Kleyn, John Hodnett, Craig Casey, Jake Flannery, Shane Daly.

Referee: Luke Pearce (RFU)

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