The world number one and defending champion recovered from a slow start at the Rothenbaum to outplay his opponent with a beguiling mix of fierce groundstrokes and deft drop shots.

Davydenko, the world number 20, led 2-0 and had break points for 3-0 in the first set before the Swiss found his rhythm. The Russian double-faulted to lose serve early in the second set and Federer took full advantage, confirming victory with a forehand winner after 71 minutes.

In the final he will either play Richard Gasquet, the French teenager who upset him in the Monte Carlo Masters quarter-finals last month, or Belgian Christophe Rochus. Their semi-final was due to follow Federer's.

The Swiss, who will be seeking to complete his grand slam collection by winning the French Open [ Images ] when it starts on May 23, has now won 40 of his 42 matches this year. He has yet to drop a set in Hamburg.