BATE 0 Chelsea 1: Giroud sends Sarri's side into knockout rounds
France striker Giroud headed in Emerson Palmieri's cross in the 52nd minute to decide a tentative contest and break his club drought dating back to May.
BATE, who hit the woodwork three times, would have been deserving of a point, but will now seek to revive their hopes in their next meeting with Vidi, who edged PAOK 1-0.
That result means the Blues, having racked up a fifth successive competitive victory, must wait until the Greek side's visit later this month to confirm top spot in Group L.
.@_OlivierGiroud_ #BATEvCFC pic.twitter.com/GhY786y8uC
— Chelsea FC (@ChelseaFC) November 8, 2018
Two goals down inside eight minutes at Stamford Bridge a fortnight ago, BATE were unfortunate not to be ahead early on home soil as Dmitri Baga crashed a long-range shot against the post.
Chelsea soon settled into a dominant share of possession without ever looking like making the breakthrough before half-time.
Giroud had fleetingly threatened with one header before the break and it was in similar circumstances that he opened the scoring, convincingly meeting Emerson's cross at the near post.
Only another moment of misfortune prevented BATE from responding quickly, with Nikolai Signevich's close-range effort coming back off the underside of the crossbar, before an unmarked Aleksey Rios skied an even more promising opening.
Eden Hazard was withdrawn just after the hour and with him went the last of Chelsea's minimal attacking verve as they settled for an uninspiring, albeit important, 1-0 victory after the upright denied substitute Evgeni Berezkin.
3 - This is the first time Chelsea have started three English players (Cahill, Barkley, Loftus-Cheek) in a European match since April 2014 vs Atletico Madrid in the Champions League (Cahill, Terry, Cole). Homegrown. #BATEvCFC
— OptaJoe (@OptaJoe) November 8, 2018
What does it mean? Scoring confidence for Chelsea strikers
Blues boss Sarri suddenly has competition for his centre-forward spot with Giroud following the lead set by Alvaro Morata against Crystal Palace and finally finding form in front of goal.
794 - Olivier Giroud's goal for Chelsea was his first in 794 minutes of action for the club, since netting against Liverpool in May. Relief. #batche #EuropaLeague
— OptaJoe (@OptaJoe) November 8, 2018
Emerson provides amid short supply of opportunities
In a match of few clear-cut chances, Emerson's wicked delivery from the left for Giroud's winner stood out as a moment of overdue quality.
Loftus-Cheek a let down
It may be a case of two steps forward and one back for Ruben Loftus-Cheek, who struggled to make any kind of impression on the match despite his team's wealth of possession, marking a stark contrast to his hat-trick heroism in the reverse fixture.
What's next?
Chelsea host an improving Everton in the Premier League on Sunday, while BATE have a break before next weekend's clash with FK Gorodeya in the Belarusian Cup.