Paris - Mesut Ozil scored as Arsenal eased to a 3-0 victory at Swedish minnows Ostersunds in the first leg of their Europa League, last-32 tie on Thursday, while Michy Batshuayi snatched Borussia Dortmund a dramatic win over Atalanta.
Left-back Nacho Monreal put Arsenal into an early lead with his fifth goal of the season, tapping in after home goalkeeper Aly Keita inexplicably let the ball slip from his grasp.
The visitors were also gifted the second goal in the 24th minute as Ostersunds tried to play their way out of their own area, with Henrikh Mkhitaryan latching onto the loose ball and seeing a low cross diverted into his own net by defender Sotirios Papagiannopoulos.
Ostersunds coach Graham Potter, a former defender for Stoke and West Brom in England, made two half-time changes in an attempt to change the flow of the game, but Arsenal all but ended the tie before the hour mark.
Mkhitaryan played in Ozil, who jinked his way through and saw his shot burst through the hands of the hapless Keita and bobble into the net.
Ostersunds were gifted a chance to at least add a memorable goal to their fairytale run, but after Tesfaldet Tekie was brought down by Hector Bellerin, David Ospina saved Tom Pettersson's injury-time penalty.
The comfortable win means that Arsenal manager Arsene Wenger will be able to rest his key players for the second leg at the Emirates in a week's time.
Batshuayi continued his good form with a late brace as Dortmund fought back to beat Atalanta 3-2 at Signal Iduna Park.
Dortmund forged ahead on the half-hour mark as Andre Schurrle did well to control Lukasz Piszczek's pass and turn the ball in for only his second goal of a disappointing campaign.
But Atalanta, who impressed in finishing ahead of Lyon and Everton at the top of Group E, scored an away goal only six minutes into the second half.
Josip Ilicic showed excellent composure to control Leonardo Spinazzola's long pass and curl into the far corner, before the Slovenian striker tapped home just five minutes later with his fourth goal of the competition.
Dortmund hit back midway through the second half, though, as Batshuayi slammed in his fourth goal in three games for the club since joining on loan from Chelsea in January.
And the Belgian striker pounced in the first minute of added time to give the two-time runners-up a precious lead in the tie.
Elsewhere, Patrick Cutrone and Fabio Borini scored as AC Milan claimed a 3-0 lead over Ludogorets Razgrad to take back to the San Siro for the second leg.
Mario Balotelli scored twice, but 10-man Nice blew a two-goal lead to lose 3-2 at home to Lokomotiv Moscow as Manuel Fernandes hit a hat-trick, while Valere Germain struck two goals as Marseille cruised past Braga 3-0.
Aritz Aduriz's double helped Athletic Bilbao win 3-1 at Spartak Moscow, while Salzburg snatched a 2-2 draw at Real Sociedad with a 94th-minute leveller.