Last season’s beaten finalists were worthy winners and the scoreline flattered Danny Wilson’s side who suffered just their second home defeat of the season.
Glasgow remain in eighth place in Pool A, but their hopes of clinging on to the last qualifying place now hinge on the results of the Sunday matches, Montpellier v Exeter and Sale v Ospreys. Warriors fans will be cheering on the two English sides.
Two late tries from sub Ollie Smith put a gloss on things for Glasgow who were distinctly second best on the night.
The loss of their captain to the sin-bin after five minutes was hardly the start they wanted but it was what they got when Fraser Brown was shown yellow for pulling down the maul as La Rochelle exerted heavy pressure on the Warriors line.
The home defence held out, suggesting Brown’s sacrifice was worth making, and Glasgow managed to force the visitors up the park, winning a penalty 35 metres from goal. Thompson struck it straight and true to put Warriors 3-0 ahead but Pierre Popelin levelled things almost immediately when Glasgow were penalised for not releasing.
Glasgow held out until Brown returned but there was little respite for Danny Wilson’s side as La Rochelle launched wave after wave of attack. The pressure eventually told after 20 minutes when Raymond Rhule burrowed through and just managed to stretch over the line. Popelin converted from wide on the right.
Glasgow needed to find a way back into the game and when they were awarded a penalty inside the La Rochelle 22 they took the safe option, Thompson kicking the three-pointer.
The stand-off then repeated the trick, reducing the deficit to a single point, after Romain Sazy was penalised for being in front of the kicker. It took Thompson through the 200-point barrier for the club.
Glasgow finally burst free in open play when Josh McKay took the ball one-handed and surged through. But, with Kyle Steyn outside him and the line beckoning, the full-back took the wrong option and cut inside and was swallowed up.
It was to prove costly. La Rochelle hacked the ball up the other end and won a lineout close to the Glasgow tryline and, from the driving maul, Paul Boudehent went over to extend the French side’s lead just before half-time.
McKay quickly atoned for his profligacy as Glasgow came flying out the traps at the start of the second half. Thompson was the creator, finding a bit of space in the midfield and embarking on a surging run before finding his full-back who ran in the score which Thompson converted to edge Warriors ahead 16-15.
If Glasgow thought they had turned the tide they were quickly disabused of this notion. La Rochelle responded in kind, adding two converted tries and two penalties in the next 17 minutes to go 21 points ahead. Hooker Pierre Bourgarit did the initial damage, piling over a little too easily for the home fans’ liking. Popelin kicked the extras then added a penalty but worse was to come.
From a lineout on the La Rochelle 22 Glasgow contrived to lose the ball and French full-back Brice Dulin hacked the ball half the length of the pitch before Pierre Boudehent gathered and crossed. Popelin again converted and followed up with another penalty as the game slipped away from the home side.
Things got a little ragged for La Rochelle towards the end and they were reduced to 13 men following yellow cards for Grégory Alldritt and Dillyn Leyds.
Glasgow at least finished with a flourish as Smith, on for McKay, scored two late tries, both of which were converted by fellow sub Duncan Weir.
In between, Ihaia West slotted over a penalty for La Rochelle.
Scorers: Glasgow: Tries: McKay, Smith 2. Cons: Thompson, Weir 2. Pens: Thompson 3.
La Rochelle: Tries: Rhule, Paul Boudehent, Bourgarit, Pierre Boudehent. Cons: Popelin 3. Pens: Popelin 3, West.
Glasgow: J McKay (O Smith 73); K Steyn, S Tuipulotu, S Johnson, R McLean; R Thompson (D Weir 68), A Price (G Horne 61); O Kebble (J Bhatti 47), F Brown (G Turner 47), Z Fagerson (S Berghan 64), S Cummings (K McDonald 61), R Gray, M Fagerson (Ryan Wilson 64), R Darge, J Dempsey.
La Rochelle: B Dulin; D Leyds, R Rhule, (E Buliruarua 73), J Danty, Pierre Boudehent; P Popelin (I West 64), T Kerr Barlow (T Berjon 64); D Priso (L Aouf 63), P Bourgarit (F Bosch 47), U Atonio (G Papidze 58), R Sazy (T Lavault), R Picquette, R Bourdeau (M Tanguy 63), Paul Boudehent, G Alldritt.
Referee: Karl Dickson (Eng)