Alexandre Lacazette was sent off as Arsenal slumped to a disappointing first-leg defeat against Bate Borisov in the Europa League last 32.
Stanislav Dragun nodded home Igor Stasevich’s free-kick for the game’s only goal just before half-time.
Lacazette had a goal disallowed early in the second half before being sent off for elbowing Aleksandar Filipovic.
A resolute Bate held on for the win, their first over an English side at home in European competition.
The Belarusian champions will now take a slender lead to Emirates Stadium for the second leg next Thursday.
It was no more than Bate deserved as Arsenal faded quickly after a bright start on a bumpy pitch and sub-zero conditions in Belarus.
Aliaksei Baga’s side were playing their first competitive match since December and doggedly held on to their lead in the second half.
Lautaro Martinez’s first-half penalty secured a narrow first-leg win for Inter Milan at Rapid Vienna in the Europa League last 32.
Substitute Christoph Knasmullner had Rapid’s best chance but saw his effort saved by goalkeeper Samir Handanovic.
Inter were without Mauro Icardi, who refused to travel and was stripped of the captaincy amid a contract dispute.
Meanwhile, Diego Lainez scored a stoppage-time equaliser to secure a 3-3 draw for Real Betis against Rennes.
Betis fell 2-0 behind inside nine minutes thanks to Adrien Hunou’s strike and an own goal from former Manchester City midfielder Javi Garcia.
Giovani lo Celso pulled a goal back for Betis but former Newcastle forward Hatem Ben Arfa restored Rennes’ two-goal lead from the penalty spot in first-half stoppage-time.
A header from defender Sidnei reduced the deficit again midway through the second half, before Lainez’s late strike secured a dramatic draw in France.
Finally, Chelsea boss Maurizio Sarri says he is looking for some consistency from his side after they claimed a 2-1 victory in Malmo in the first leg of their Europa League last 32 tie.
Sarri said Chelsea needed to approach every match with the same level of application, determination and attention.
“You know very well that, if you are in bad mental condition in England, in 10 days you can lose three or four very important matches. So we need consistency. We have to approach every match in the same way. It’s not easy, but we have to try,” the Italian added.