Arsene Wenger has praised Olivier Giroud for putting in a proper striker's performance in Arsenal's 3-0 win over Olympiacos which saw them into the knock-out stages of the Champions League. The Frenchman scored his first hat-trick of his Arsenal career, and received major praise from the manager for the mental strength shown by the striker which saw him overcome a few uncomfortable situations and help the Gunners through.

A beautiful pass from Mesut Ozil saw Aaron Ramsey in space for the first goal. Ramsey pulled a brilliant cross for Giroud to attack on the near post. The Frenchman headed the ball low under the goalkeeper, who got a hand to it but the ball squirmed into the net, much to the relief of the Gunners.

For the second goal, Giroud made a late run into the box for Joel Campbell to thread a beautiful pass into his stride which he finished with aplomb. He completed his hat-trick with a penalty after an Olympiacos defender had handled a Nacho Monreal cross inside the penalty box.

The Gunners, who have failed to progress out of the round of 16 for the last five years in succession, will know their fate on Monday following the draw, with Chelsea and Manchester City the other two clubs in the competition. Manchester United will contest in the Europa League following their 3-2 loss to Wolfsburg in their last group game.

"It was a perfect performance because he scored a header, one with a good combination, thanks to a good pass by Campbell, and also a penalty on top of that. He was sometimes in uncomfortable positions but he fought like mad and he has shown skill and character. I always defended Olivier on the character side because he has always had something special on that front. He showed that in the game again today," Wenger told Arsenal's official website.

The manager also waxed lyrical about Campbell who had his best game in an Arsenal shirt thus far, stating, "A former player for Olympiacos was firstly a former player of Arsenal. Joel Campbell is a very good player who has individual skill but what I also like is that he is a real team player who fights for the team. On top of that he will get to an age where he becomes a real professional footballer. He came from Costa Rica at a very young age, went to four different clubs on loan and that made him tough. Now he gets his chance and he is getting stronger in every game."