Arsenal look set for a place in the Champions League group stage after Spain midfielder Cesc Fabregas scored twice in a 3-0 qualifying win at Dinamo Zagreb on Tuesday.
Dutchman Robin van Persie grabbed the other goal as last season's finalists made the breakthrough following a goalless first half in their third qualifying round, first leg game.
Arsenal, beaten by Barcelona in the May final in Paris, were rewarded for their patience after Dinamo had packed their half in a bid to frustrate Arsene Wenger's side.
Former European champions Benfica had to settle for a 1-1 draw at Austria Vienna in the night's other qualifying game.
Nuno Gomes gave the Portuguese an early lead but Jocelyn Blanchard struck the equalizer just before halftime to keep the Austrians in the tie before the second leg in two weeks' time.
Arsenal's game in Croatia was decided in little more than 60 seconds midway through the second half.
Fabregas opened the scoring in the 63rd minute with a fine angled shot after a neat lay-off by Van Persie and the Dutchman made it 2-0 in the 64th minute, racing through to pounce on a long ball from Alexandr Hleb.
Arsenal all but wrapped up the tie in the 78th minute, when Fabregas went on a solo run, accelerating past two Dinamo players and tucking his angled shot inside the post.
The victory will add to speculation about the future of Arsenal's Spanish forward Jose Antonio Reyes, a transfer target for Real Madrid and who spent the evening on the bench.
Reyes's agent Rodriguez de Moya said earlier on Tuesday that a move to Madrid could be torpedoed if the forward played in Zagreb as he would then be cup-tied in Europe all season for Real.
The rest of the final qualifying round, first leg matches followed last night.
Among the games, last year's European champions Liverpool host Maccabi Haifa at Anfield, AC Milan are at home to Red Star Belgrade, Valencia take on Salzburg and Ajax Amsterdam play FC Copenhagen in the race to the lucrative group stage.
Meanwhile, Arsenal defender Sol Campbell has completed his move to Portsmouth.
The 31-year-old, released by the Gunners at the end of last season, signed a two-year deal at Fratton Park, having passed his medical on Monday.
Portsmouth manager Harry Redknapp was delighted with his new signing.
"I told him Portsmouth are a club going places, a good club to come to," Redknapp said. "It's a very ambitious club now. We are going to keep moving forward and he can be part of something very exciting. So I think he was up for that."