Exeter 7 Bordeaux-Begles 13
Exeter's European Champions Cup campaign is almost certainly over as they succumbed to another defeat at Sandy Park.
The Chiefs squandered a host of chances as they fell to a third consecutive defeat in the competition, which leaves them stuck at the bottom of Pool Five with only two points - 10 behind leaders Clermont.
Jack Maunder scored the Exeter try which Gareth Steenson converted. Baptiste Serin scored a try and a penalty for the French with Ian Madigan kicking a conversion and Lionel Beauxis a late penalty.
The visitors had an early chance to open the scoring when flanker Loann Goujon charged down a clearance from Maunder to put the home side on the back foot.
Skilful passing gave Bordeaux wing Blair Connor a good opportunity for a try but he was forced into touch narrowly short.
Poor tactical kicking from the French surrendered the early initiative with a brilliant defence splitting run from Lachie Turner almost bringing the first try for the hosts.
The visitors were forced to rely on box kicking from their scrum half and captain Serin to relieve the pressure inside the first 20 minutes, which remarkably ended scoreless.
A high tackle by Exeter lock Jonny Hill on his opposite number Tom Palmer was penalised, securing the French a platform in the home half but despite a strong burst down the right flank from Nans Ducuing the Chiefs' line remained intact.
Back came Exeter, who were denied a try when Turner knocked on a well-judged kick ahead from Henry Slade as the full-back dived for the line.
After 30 minutes Exeter deservedly took the lead when Maunder scored his first try for the club as he was on hand to support a break from Ollie Devoto to dash over.
The fog then began to descend on Sandy Park with visibility being greatly reduced but it was still sufficient to see Serin put Bordeaux on the scoreboard with a penalty to leave his side trailing 7-3 at the interval.
After the restart, the fog relented and the visitors made a half-time change with Luke Jones coming on in place of Palmer.
Two minutes later Exeter also made a change at lock with Geoff Parling leaving the field with a shoulder problem.
Ollie Atkins replaced him as the hosts maintained control but once again they missed an opportunity to make it count as the ball slipped from Steenson's hands as he strained for the touchdown.
The power of the Exeter scrum was becoming an increasingly major factor as they regularly shunted the opposition back at almost every engagement.
In an effort to shore up their beleaguered pack, Bordeaux made four forward replacements in one hit with the home side also replacing both props and introducing Will Chudley at scrum-half.
The changes soon much a huge difference as the French pushed Exeter off their ball at a scrum 10 metres out, which allowed Serin to score a try under the posts for Madigan to convert. Serin was injured in the process and departed for a head assessment but his side led 10-7 at the end of the third quarter.
Beauxis replaced Madigan at fly-half and soon extended Bordeaux's lead with a penalty before a superb run from James Short appeared to see him score. However, after consultation with the TMO, the Exeter wing was adjudged to have knocked on - meaning Chiefs are almost certainly out of Europe.