A second-half goal by Robin van Persie gave Arsenal a 1-0 victory over Steaua Bucharest on Tuesday to tighten their grip on Champions League Group H.
The Dutchman rifled home the winner after Togolese strike partner Emmanuel Adebayor found him completely free in the area after a quick counter-attack down the left in the 76th minute.
Arsenal, who now have a maximum six points from two matches, dominated the match but created few clearcut scoring chances against the Romanian side.
"Steaua were well-organised...it was a question of patience for us," Arsenal manager Arsene Wenger told reporters.
"It was a match in which we suffered more than in the previous match against Sevilla," Wenger said of their 3-0 victory over Spain's UEFA Cup holders two weeks ago.
Steaua's Italian coach Massimo Pedrazzini fielded a surprisingly attacking line-up with four forwards, but midfielder Nicolae Dica and substitute Victoras Iacob both missed good second-half chances.
Dica might have scored his fifth goal in eight Champions League matches, but his long-distance lob over Arsenal goalkeeper Manuel Almunia was headed clear by Kolo Toure.
A neat through-ball by Banel Nicolita set up the unmarked Iacob, who had come on for Valentin Badea in the second half, but the striker sent his curling shot over the top.
Arsenal failed to find much in the way of scoring opportunities before Van Persie's winner.
The Premier League leaders only really threatened with a shot from Spain midfielder Cesc Fabregas in the early stages and a deflected cross by Van Persie which was just saved by Steaua's Colombian goalkeeper Robinson Zapata on the line.