Arsene Wenger said it was "difficult to understand" why Aaron Ramsey's goal was ruled out for offside in Arsenal's goalless Premier League draw with Liverpool on Monday.
Liverpool dominated the first half at the Emirates Stadium on Monday, but should have fallen behind when Ramsey found the back of the net after 10 minutes only to see the flag raised.
Replays showed the Wales midfielder was clearly onside and Wenger was not impressed with the decision after watching his side fail to win for a second home game in the top flight following their 2-0 defeat to West Ham on the opening weekend.
"We made chances in both halves and were unlucky because we scored a goal that was cancelled, which was difficult to understand," the Arsenal manager told Sky Sports.
Philippe Coutinho hit the crossbar after only two minutes and struck a post with a shot that Petr Cech got a fingertip to at full stretch.
Cech produced another outstanding stop to somehow deny Christian Benteke from close range and Wenger was pleased to see the former Chelsea goalkeeper show his class after a poor debut against West Ham.
"He did a good job as he kept us in the game in important moments, that's what you expect from him. He had a good game," the Frenchman said.
Wenger was again left to rue his side's lack of a cutting edge, though, as they failed to find the back of the net at home.
He added: "We struggled to score goals in the second game at home. We need to play better in our opponent's final third."
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