Arsenal defender Laurent Koscielny believes the bitter experience of losing to League Two minnows Bradford will help the Gunners avoid a second humiliating defeat at Brighton in today's FA Cup fourth-round tie. The FA Cup looks Arsenal's most realistic chance of silverware this season, but if they are to progress in the competition they must overcome a potentially tricky test against Championship opposition in the last 32. Gus Poyet's Brighton side are challenging for a place in the second-tier play-offs and confirmed their threat in the previous round when they knocked out Premier League strugglers Newcastle. That will signal a warning for Koscielny and his Arsenal teammates, who are still smarting from an embarrassing defeat on penalties to Bradford in the League Cup quarter-finals. "The lesson is that it is not just with your quality that you can win a game. All of the team must concentrate and want the same thing," said Koscielny. "We must be prepared to fight and stay focused on our quality and play our football. If we play like this then we can win every game. The smaller teams always want to win against the big teams. It will be hard." Arsenal's visit will give Brighton the chance to show how far they have come since their 6-1 defeat to Liverpool in the fifth round of the competition last season. Three own goals added to Brighton's misery that day and former Chelsea star Poyet said: "I'm learning from last year. "I want to make sure we don't give everything in the first 30 minutes. We need to be a bit smarter. I want to see my team playing the same kind of football but more intelligent."