Glasgow Warriors' hopes of reaching the Heineken Champions Cup knockout stages all-but ended following defeat to Ronan O'Gara's La Rochelle at Scotstoun.
The hosts took an early lead with a smartly executed line-out drive for hooker Fraser Brown to touch down, with Adam Hastings converting.
La Rochelle kept on their shoulder with a try from winger Jules Favre and took the lead five minutes from the break when centre Levani Botia touched down, with Brock James converting, after good work by scrum-half Alexi Bales.
Glasgow made nothing of second-half pressure and in the final minute referee Wayne Barnes ruled out a score by lock Scott Cummings, the TMO having noted rough play by Warriors number eight Matt Fagerson, who was shown a red card.
La Rochelle, including only four of the players from the side that lost to Glasgow a week ago, kicked off on a wet, windy and already dark afternoon.
The first chance fell to Glasgow in the eighth minute when a long pass set centre Huw Jones free up the right wing. His chip into the 22 sat up for scrum-half Ali Price but he could not hold the wet ball.
A series of penalty awards by Barnes kept Glasgow pressing. After 16 minutes, from a close in line-out, the Glasgow pack surged over for a try from Brown.
La Rochelle pulled back five points four minutes later.
The ultimately fine move had a ludicrous opening. Number 10 James lined up a penalty just inside the Warriors half.
The ball was blown by the strong cross wind far from its target and just over the home 22, but it was La Rochelle that recovered possession, with centre Brieuc Plessi sending his wing partner Favre in at the corner.
The notable feature of the half was the visiting pack's ability to retain possession in such unfavourable conditions, so dominating possession.
Five minutes from the interval, Bales found space to get close to the home goal-line from where Botia scored by the posts for James to convert and the French side went in leading 12-7.
Glasgow got more possession from the restart but were not able to take advantage of penalties that got them into the opposition 22 and which, in retrospect, might have been kicked for points.
In the 57th minute, Nick Grigg got closest when held up under the crossbar.
Glasgow continued to press on the line with La Rochelle scrum-half Bales sin-binned but ultimately Nikola Matawalu could not hold a long pass.
With seconds remaining Cummings finally got over the line. However, after consulting the TMO, referee Barnes not only ruled it out but also sent off Fagerson.