Arsenal have beaten Celtic 2-0 in their play-off tie, giving them a great chance of reaching the group stages of the Champions League.
They took the lead two minutes before half time when William Gallas scored past Artur Borus.
The other was an own goal by Celtic skipper Gary Caldwell. The second leg is next week at the Emirates Stadium.
It's the first time the Scottish club have lost at home to an English team in Europe in 26 years.
Celtic have beaten teams like AC Milan, Juventus and Manchester United in recent years, but they could not sustain any attacking threat against the Gunners.
Arsenal boss Arsene Wenger said he was pleased with his team's performance, and described William Gallas as being "in the best form of his last two years.
Chelsea v Sunderland
In the Premier League, Chelsea came from a goal down to beat Sunderland 3-1 at the Stadium of Light.
Darren Bent gave Sunderland a first-half lead before Michael Ballack, Frank Lampard, and Deco struck back for Chelsea.