Johann van Graan and Ronan O'Gara on Bath loss to La Rochelle

Bath boss Johann van Graan was left to reflect on “small margins” after his team lost their opening Investec Champions Cup game 24-20 against La Rochelle.

The Gallagher Premiership leaders launched a powerful second-half fightback, scoring two converted tries from 15 points adrift, but La Rochelle had just enough in the tank for a priceless away win.

“It is an 80-minute game. We got ourselves back into at 21-20, and we could not convert a couple of opportunities in the last few moments,” Van Graan said.

Bulls Director of Rugby Jake White on the weather conditions in London ahead of the Saracens clash

Storm Darragh is set to bring strong winds and heavy rain to London this weekend, but White believes he has a matchday squad that can adapt to all conditions.

Bulls Director of Rugby Jake White on the weather conditions in London ahead of the Saracens clash

Storm Darragh is set to bring strong winds and heavy rain to London this weekend, but White believes he has a matchday squad that can adapt to all conditions.

“It was a real battle, and we are disappointed. The margins are so small.

“We execute one more opportunity, we win by a point and we are all happy I thought we competed, the scrum was a real battle, the maul, the kicking game – both sides got some aerial dominance.

“I am content with the fact we played our game, we mixed it with one of the heavier teams in world rugby.”

La Rochelle raced clear through tries from flanker Oscar Jegou, prop Reda Wardi and scrum-half Tawera Kerr-Barlow, while fly-half Ihaia West kicked three conversions and a later penalty.

Bath were in deep trouble at half-time, managing only two Finn Russell penalties, yet they stirred after the break as hooker Tom Dunn and lock Quinn Roux claimed touchdowns, with Russell adding the extras.

Despite swirling rain and a gusting wind, a compelling contest unfolded, although it ramps up pressure on Bath, despite a losing bonus-point, to potentially win at least two of their last three pool games as they chase a last-16 place.

They tackle Benetton in Italy next, with Clermont Auvergne and Leinster looming as testing opponents in January.

“When you play in conditions like this, the game throws stuff at you,” Bath captain Charlie Ewels told Premier Sports.

“I liked how we stayed calm and I liked how we never played scoreboard pressure when we were 15 points down. It gave us opportunities to win the game, but we didn’t take them.

“It feels like a Test match, it feels like every play was a big play, I am proud of the effort, but you want to win these ones and I feel like we are in a place now when we can win these big ones.”

La Rochelle head coach Ronan O’Gara said: “We were clinical for 40 minutes. We have an exceptional driving maul, and then it was exceptional hands from Tawera Kerr-Barlow for his try.

“We then had a very poor first 10 minutes of the second half and put ourselves under unnecessary pressure, and we conceded a soft maul try.

“We should have been double figures better than Bath, but it was all about the win tonight.

“We have been terribly inconsistent, and we need to get our game going for more than 50 minutes.”