Karlovic serves up danger

If anything can knock Roger Federer out of his swaggering stride towards a seventh successive Wimbledon final it is the booming serve of the gigantic Croatian Ivo Karlovic. The tallest man in the draw at 6ft 10in, Karlovic held too many aces yesterday against the former Australian Open finalist Jo Wilfried Tsonga, who was urged on in vain by most of the Court One crowd in a war of attrition and tie-breaks.

There were only two break points - both against the ninth-seeded Tsonga - in 2hr 44mins of ferocious serving. Karlovic, the 22nd seed, took the second of them propel himself to a commendable 7-6, 6-7, 7-5, 7-6 victory. The man who sent down a record 55 aces in one match at Roland Garros recently added another 46 to his haul against Tsonga and it was appropriate that the last of them came on match point after the Frenchman had saved one against him on his own serve.

It is not the prettiest sight in sport watching Karlovic going about his business but it is frighteningly effective. "I know I can serve even better than that," said Karlovic, who has annually been tipped as a dark horse here but has fallen at the first hurdle on his last four visits. Federer, who dropped his first set of the tournament getting past Germany's Philippe Kohlschreiber 6-3, 6-2, 6-7, 6-1, will be more concerned about the possibility of meeting Karlovic in the quarter-finals than meeting Robin Soderling in Monday's fourth round.

Soderling, the surprise French Open runner-up earlier this month, was beaten for the 10th time in as many meetings by Federer in that Roland Garros final. The 13th-seeded Swede qualified for an 11th attempt by dealing efficiently with the Spanish challenge of Nicolas Almagro 7-6, 6-4, 6-4. @Email:[e-mail]