Goals from academy graduates Joe Willock and Bukayo Saka helped Arsenal overcome a difficult test against Eintracht Frankfurt and begin their Europa League campaign with a victory.
Willock put the Gunners in front with a deflected shot in the first half before Saka smashed in his first senior goal for the club in the 85th minute.
Pierre-Emerick Aubameyang added a third two minutes later as Arsenal ended their three-game winless run.
The Gunners had created further chances but also relied on goalkeeper Emiliano Martinez to come to the aid of their fragile defence.
The Argentine produced excellent low saves to deny Filip Kostic and Andre Silva in the first half.
The second period was frantic in front of a vociferous home crowd with Arsenal’s late goals only coming after Dominik Kohr was shown a second yellow card for a cynical foul.
The Gunners, beaten finalists in last year’s Europa League, are top of the early Group F table on goal difference after Standard Liege beat Vitoria in the night’s other game.
At Old Trafford, Teenager Mason Greenwood’s first senior goal ensured Manchester United made a winning start to their Europa League campaign against Astana at Old Trafford.
On a night the 17-year-old will never forget and with the visitors from Kazakhstan threatening to hold out for a draw, Greenwood produced a clever finish in front of the Stretford End to become United’s youngest scorer in Europe.
Brazil midfielder Fred hit the bar from 25 yards before forcing a fine save from a free-kick, while England forward Marcus Rashford wasted a string of chances against the European minnows, who did not register a shot on target.
But frustration turned to celebration when Greenwood, who has been at United since the age of six, popped up with the winner.
Even after his goal, a much-changed United continued to waste chances.
Diogo Dalot blazed over from close range after Nenad Eric had kept out substitute Jesse Lingard’s thunderous attempt.
Rangers paid the perfect tribute to late captain Fernando Ricksen by edging Feyenoord in a rousing Europa League win at an emotional Ibrox.
Sheyi Ojo’s first-half thunderbolt secured three points after James Tavernier missed an early penalty.
There was a minute’s silence pre-match and applause in the second minute in tribute to Ricksen, who died on Wednesday after losing his battle with motor neurone disease.
Rangers go level with Porto in Group G.
The Portuguese side beat Young Boys 2-1 at home, with Steven Gerrard’s side travelling to Switzerland in their next match.
Feyenoord, meanwhile, will host Porto next, having grown into the game at Ibrox late on but failing to land a decisive blow as Allan McGregor made several good saves to keep them out.