World number one Roger Federer [Images] warmed up for an explosive semi-final showdown with Mario Ancic with a battling 7-5, 7-5 win over Russia's [Images] Nikolay Davydenko at the World Indoor Tournament in Rotterdam on Friday.

Ancic completed a successful day for Croatia by beating third seed Tim Henman 7-6, 7-6, while Ivan Ljubicic reached his second semi-final in as many weeks following a 3-6, 6-4, 6-2 victory over Paradorn Srichaphan [Images].

Ljubicic will meet former Australian Open champion Thomas Johansson, who defeated Czech Radek Stepanek 6-2, 7-6.

Federer toyed with Davydenko in a 100-minute contest before ending the sixth seed's run at the Dutch port city.

"It was fun on one side but it was a very tough battle and I'm happy to be through to the semis," said Federer.

The Swiss gave Davydenko a glimmer of hope in the opening game when the Russian earned a break point, though that was as good as it got for Davydenko, who kept being drawn into long rallies until Federer unleashed one of his spectacular winners.

The top seed wasted a set point in the 10th game on Davydenko's serve before finishing the job two games later.

Davydenko had his chances to take the match into a third set, earning two break points in 11th game of the second but Federer safely negotiated that danger.

Henman, who lost to Ancic at Wimbledon last year, once again came up short against the big-serving Croatian.

Four consecutive breaks of serve in the opening set displayed both players' nerves before Ancic managed to get his fierce serve going in the tiebreak, winning it 7-5 with a thundering unreturnable delivery.

The second set followed in identical fashion, with a dumped volley from Henman sealing Ancic's victory 7-4 in the breaker.

"He can generate so much power with limited effort and that's tough to deal with," said Henman.

"With two tiebreaks it's always going to come down to a couple of points and credit to him, he took them."

UPPER HAND

Earlier, Sweden's Johansson enjoyed the upper hand for most of his match against Stepanek despite losing serve in the fifth game of the second set.

The Swede kept focus to level before securing victory 7-5 in the tiebreak with his second match point.

"I was in the final here seven years ago and it will be good if I can get there again," said Johansson, who was beaten by Jan Siemerink in 1998.

Ljubicic, beaten by Joachim Johansson in the Marseille final last week, had to bide his time on Friday before finding his rhythm.

"I was so tired after yesterday's match that it wasn't easy for me to concentrate in the beginning," said Ljubicic, who also reached the last four here in 2002.

"I was getting easily distracted by things I shouldn't have so that took the first set away. In the second, I decided to focus on each point and that made the difference."

While Paradorn grabbed a single break to take the opening set, he failed to maintain the momentum in the second and started to drag his feet around court.

The Asian number one looked increasing frustrated with himself in the third, generating unforced errors.

A delighted Ljubicic capitalised and ended the match with a scorching backhand down the line winner.

"Three years ago when I reached the semis, I was so happy because I wasn't used to playing on the Saturday of a tournament," joked Ljubicic, who has won 15 of his 19 matches this year.

"But playing a semi now is not a big deal as my standard has changed."

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