EDINBURGH kept themselves firmly in the hunt for a place in the Champions Cup knockout stages yesterday after securing a bonus-point win in a hard-fought battle.

Mike Blair’s team may not have been at their swashbuckling best against dogged opponents, but they demonstrated considerable character to ensure they ended up on top.

Having picked up a losing bonus in their defeat at Saracens last Sunday, the capital club may not need too many more points to ensure they go through to the last 16 by finishing in the top eight in Pool A. Rather than work out what precisely may be required from his team’s two remaining games, however, Blair would prefer to keep it simple.

“We’ll just wait and see – and try to win all our games,” the head coach insisted, before praising the fortitude shown by his side. “Today was one of those days where we created a fair bit but the ball wasn’t sticking.

“Sometimes you have days like that and I’m just pleased it came on a day where we were still able to get five points in the bag. We found a way to win.

“I was really impressed with [Castres]. They’ve got size, they’ve got cohesion, and they don’t do a huge amount of special things as a team, but they stick in there. And their set-piece was good, so that put pressure on us, especially in the first half when the breeze was against us.”

Edinburgh had been forced into a late change to their starting line-up when Duhan van der Merwe failed a fitness test on an ankle injury. Damien Hoyland came into the side, with Wes Goosen swapping wings.

Van der Merwe should be fit for Friday’s first 1872 Cup match at Glasgow, but Stuart McInally is a doubt after sustaining a head injury in the opening minutes. Blair Kinghorn came off ten minutes after the hooker because of a back spasm, and it remains to be seen if he will be available for the trip to Scotstoun.

Edinburgh took those enforced alterations in their stride, and opened the scoring midway through the half when Bill Mata forced his way over from close range and Emiliano Boffelli added the first of three successful conversions.

Castres hit back within minutes when hooker Pierre Colonna collected a line-out deflection and raced to the line for an unconverted try, and then after half an hour they went ahead with another five-point score when scrum-half Julien Blanc finished off on the right.

Edinburgh hit back, however, and regained the lead through a penalty try, awarded after Quentin Walcker came in from the side and pulled the maul down. The loosehead prop was shown a yellow card for the offence, but the 14 men had the last word in the first half when a Julien Dumora penalty took the score to 14-13.

Edinburgh gave themselves some breathing space early in the second half when Charlie Savala finished off from a pass by James Lang. The try, made possible by an excellent run from Luke Crosbie deep into the 22, was converted by Boffelli from in front of the posts.

The home team were soon under renewed pressure, but they got the bonus try when a kick ahead by Lang was fumbled by Martin Laveau as he attempted to touch down. Following up at lightning speed, scrum-half Ben Vellacott made no such mistake, dotting down to leave Boffelli with a simple conversion.

That seemed to be that, but Castres hit back immediately, with Adrien Seguret dashing through a gap in the defence after Edinburgh failed to deal with the restart. Ben Botica converted, and perhaps for a moment or two there was an element of self-doubt within the home ranks.

However, they stuck to their task well in defence, and once back in possession ran down the clock astutely before a Boffelli penalty completed the scoring.

Scorers, Edinburgh – Tries: Mata, penalty try, Savala, Vellacott. Cons: Boffelli 3. Pen: Boffelli.

Castres – Tries: Colonna, Blanc, Seguret. Con: Botica. Pen: Dumora (40).

Edinburgh: E Boffelli; D Hoyland, M Currie (C Dean 49mins), J Lang, W Goosen; B Kinghorn (C Savala 14), B Vellacott; P Schoeman (B Venter 63), S McInally (T Cruse 4), W Nel (A Williams 63), G Young (M Sykes 58), G Gilchrist, J Ritchie (capt), L Crosbie (B Muncaster 69), V Mata.

Castres: J Dumora (T Larregain 54); M Laveau, A Zeghdar, A Seguret, A Bouzerand; B Botica, J Blanc (R Kockott 63; Q Walcker (L Guerois-Galisson 54), P Colonna (B Humbert 52), A Azar (A Guillamon 54), G Maravat (F Vanverberghe 54), T Hannoyer, B Delaporte (capt), A Usarraga (J Raisuqe 75), K Kornath (B Cope 54).

Referee: T Foley (England). Attendance: 5,567.