Arsenal's dream start at Rennes turned into a nightmare as they saw Sokratis Papastathopoulos sent off before going on to lose the first leg of their Europa League tie 3-1 in France.
Alex Iwobi gave the Gunners the perfect start when his third minute cross found its way into the far corner, and from then on Arsenal looked largely in control until the game turned just before half time.
Sokratis was sent off when a third clumsy challenge saw him receive his second yellow card in seven minutes, and to make matters worse, Benjamin Bourigeaud lashed in a fantastic equaliser from the resulting free kick.
Unai Emery's side had their back to the wall in the second half, and endured more misfortune when Nacho Monreal score on own goal on 65 minutes, before a tricky task turned into a serious mountain to climb when the excellent Ismaila Sarr headed in a third Rennes goal two minutes before time.
Arsenal had to turn around a first-leg deficit in the previous round after slipping to defeat at BATE Borisov but at least have an away goal to take back to north London next week.
Before that, however, they face Manchester United in a crucial Premier League game in the battle for the top four, with Emery knowing they'll have to play better in both to keep both avenues for a Champions League return open.
Applications for tickets could have sold out Roazhon Park three times over and the home support made a cauldron of noise which only intensified as their team took the tie by the scruff of the neck.
Europa League round-up
Villarreal were also 3-1 winners away at Zenit St Petersburg. Former Leicester midfielder Vicente Iborra gave the Spanish side the lead but Sardar Azmoun immediately equalised.
Second-half goals from Gerard Moreno and Manu Morlanes put the LaLiga team in control heading back to the Estadio de la Ceramica next week.
Dinamo Zagreb were the other winners in the early kick-offs as Bruno Petkovic's penalty just before half-time was enough to beat Benfica 1-0 in Croatia.
Sevilla had to settle for a 2-2 draw at home against Slavia Prague, despite going ahead after only 24 seconds through Wissam Ben Yedder. Miroslav Stoch levelled things up for the Czech side but Munir El Haddadi quickly restored the host's advantage before Alex Kral equalised again before the break.
Eintracht Frankfurt and Inter Milan drew 0-0 in Germany after Marcelo Brozovic saw his first-half penalty saved by home goalkeeper Kevin Trapp.
UEFA Europa League Round of 16 results
Rennes 3-1 Arsenal - Opta stats
- Rennes are unbeaten in five games in Europe (W4 D1), their longest-ever run without defeat in European competition.
- Arsenal have lost away to a French side for the first time ever in European competition (W8 D5 L1).
- Arsenal have lost consecutive away games in Europe for the first time since September/November 2015, when they lost to Dinamo Zagreb and Bayern Munich in the Champions League.
- The Gunners have conceded 3+ goals for the first time in their last 23 European games, since losing 5-1 to Bayern Munich in March 2017 in the Champions League.
- Arsenal have picked up red cards in consecutive games (v Rennes and Tottenham) for the first time since September 2015 (v Chelsea and Dinamo Zagreb).
- Arsenal have had a player sent off and scored an own-goal in a game for the first time since September 2015 (v Chelsea in the Premier League).
- Petr Čech returned to Roazhon Park with Arsenal, 14 years & 288 days after making his last club appearance there as a Rennes player in May 2004.
- Alex Iwobi has scored five goals for Arsenal in all competitions this season – his best return in a single campaign for the Gunners.
- Alex Iwobi’s opener on 3 minutes 0 seconds was Arsenal’s fastest goal in European football since Lukas Podolski scored in the Champions League (2 mins 1 sec) against Galatasaray in December 2014.
- Rennes striker Ismalia Sarr has been directly involved in six goals in the Europa League this season (four goals, two assists); more than any other player for the French side.