LONDON: A nervy Arsenal showed the mental strength manager Arsene Wenger was looking for, even if Olivier Giroud scored for both sides, by beating Sunderland 3-1 to go second in the Premier League on Saturday. With a crunch Champions League match looming against Olympiakos Piraeus in Athens next week, and eight players currently on the injured list, Arsenal needed a win after a run of three disappointing league games. 'I was more nervous than usual today because I knew it was a very important game for our season,' Arsenal manager Arsene Wenger told reporters. 'We were edgy, nervy in the first half against a very well organised team who were very impressive on the counter attack as well,' added the Frenchman, whose side avoided any fresh injuries. 'But in the second half I think we have shown mental strength and desire in our game and more fluency as well. All was not perfect of course, but the team have shown mental strength after a goal before halftime.' That was on own-goal by Giroud that levelled the score at 1-1 after Joel Campbell had put Arsenal ahead in the 33rd minute, running onto a defence-splitting pass from German World Cup winner Mesut Ozil to score from 10 metres. That was the home side's first and only shot on target in the first half, with Sunderland having the more plentiful and better chances. Even after Giroud scored at the right end with a well-placed header midway through the second half, Sunderland still looked capable of getting a draw before Aaron Ramsey sealed the win in the last minute. Arsenal, who need to win on Wednesday by any result other than 1-0 or 2-1 to reach the knockout phase of the Champions League, did what was needed on Saturday but will have to raise their game in Greece. The result left Sunderland fourth from bottom, just above the relegation zone. But manager Sam Allardyce had nothing but praise for his players, saying it was their best performance since he took over two months ago. 'I've been here (at Arsenal) with Bolton, Blackburn, West Ham and Newcastle and I've never been here and created as many chances with a team than we created today, that's for sure,' he told reporters.