LONDON (AFP) - Arsenal manager Arsene Wenger urged his side to focus on Tuesday's last 16 Champions League first leg clash with Bayern Munich following the Gunners' shock FA Cup loss at home to Blackburn Rovers.

Boyhood Arsenal fan Colin Kazim-Richards scored the only goal in the 72nd minute as second-tier Blackburn advanced into the quarter-finals of the FA Cup with a 1-0 win at the Gunners' Emirates Stadium on Saturday.

Arsenal haven't won a major trophy since last lifting the FA Cup in 2005 and the team were booed off by their own supporters at full-time.

"I couldn't see how we could lose the game because we had a lot of the ball and they had one shot on goal but they defended well and it's the kind of game you can lose if you make a mistake at the back like we did," said Wenger after Arsenal's first FA Cup defeat by lower league opponents in his 17 years as Gunners boss.

"We have just lost a game today and we don't need to think too much about the eight season (trophy drought), the players who played today didn't play eight seasons ago and we must focus on the next game."

Wenger, who controversially left Jack Wilshere, Theo Walcott and Santi Cazorla on the bench, only for Richards to score shortly after the trio all came on, said he'd no problem with Arsenal fans' jeers at the end of the match.

"What do you expect, people to applaud when you lose a game like that? It's absolutely normal." Saturday's defeat was the second time this season Arsenal, a huge 21 points behind Premier League leaders Manchester United, had been knocked out of a domestic cup competition by lower league opposition after losing to fourth-tier Bradford in the League Cup.