Henman enjoyed himself against the world number one

Henman now faces Lleyton Hewitt in the last four, after a dominant display against the current world number one.

The British favourite wasted four break points on his way to deservedly taking the opening set.

The second set went to a lengthy tie-break, with Henman holding out to secure his sixth win in seven matches against the Swiss player.

From the very start, Henman looked to have the weapons to beat Federer and used them astutely to break him in the eighth game of the opening set.

Predictably, the fifth seed's game then became shaky, and he sent down a double fault on his second set point.

But he made no mistake with the third when Federer loosely tapped a backhand into the net.

Hewitt's a guy I've really struggled against and I'm really looking forward to my first win Tim Henman

An early exchange of breaks set the tone for a nervy second set as both players struggled to hold serve.

Henman, three times a losing finalist in Rotterdam, succumbed again in the sixth, dropping his serve with yet another double fault.

Federer, however, failed to take advantage as the Briton immediately broke back with an emphatic smash and the set headed into a tie-break.

The top seed charged into a 5-1 lead and although Henman battled his way back to 6-6 the Briton had to fight off five set points before finally clinching victory.

"Tonight we didn't play our best tennis," Henman said. "Balls were flying around and it was easy to lose control.

"My record against Roger is something I can't explain. My style of play obviously has an impact on his game.

"But it also puts it into perspective my record against Hewitt," he added, referring to his six defeats by the Australian.

"Hewitt's a guy I've really struggled against and I'm really looking forward to the opportunity to get my first win."