Arsenal 2 Olympiacos 2: Teenager on target as Arsenal triumph

The 18-year-old winger scored the opener at the Emirates, with Andre Santos adding another, before David Fuster made for a tense finish.

But the performance of Oxlade-Chamberlain, who was playing for Southampton in League One last season, provided the main talking point.

“It was a really good experience,” he said.

“It’s a big step up, but I want to play at the top level and I have plenty more time to play in the Champions League.

“It’s my first time in the Champions League and I’m glad we’ve achieved three points.”

Goalkeeper Wojciech Szczesny had to be on his guard in the second half as Arsenal, without manager Arsene Wenger owing to suspension, held on.

“It was a very tough game, we knew it would be,” he added.

“You have to give credit to our defence for keeping the score at 2-1. They put a lot of pressure on us and we produced a great defensive performance in the second half.”

Elsewhere, Lionel Messi scored twice as Barcelona claimed their second consecutive 5-0 win after outclassing hosts BATE Borisov in Minsk.

Fresh from hitting a hat-trick in his side’s Primera Liga win by the same score over Atletico Madrid on Saturday, Messi blasted home in the 38th and 56th minutes to put the game out of sight.

Also in Group H, AC Milan had to work hard to dispatch Viktoria Plzen 2-0 at the San Siro, waiting until the 53rd minute until Zlatan Ibrahimovic finally broke the deadlock from the penalty spot.

Massimiliano Allegri’s men put the points beyond doubt when Antonio Cassano netted the second in the 66th minute.