The Aceman Cometh Federer`s Way

The latest masterclass in delivery took Karlovic`s ace count to 137 in four matches and provided the best grand slam result of his career.

Ivo Karlovic served 35 aces on Monday to reach the business end of a grand slam for the first time and give Roger Federer plenty to think about.

Karlovic, the 30-year-old from Croatia, has a serve that has defied attempts to return it to any effect at this year's Wimbledon and it proved too much for seventh-seeded Spaniard Fernando Verdasco, who succumbed 7-6 6-7 6-3 7-6.

The latest masterclass in delivery took Karlovic's ace count to 137 in four matches and provided the best grand slam result of his career.

"Yeah, I mean, on my serve I was feeling good," Karlovic said with a certain amount of understatement.

"In the last tiebreaker, he returned a few serves unbelievably but other than that, I was feeling good on my serve."

Karlovic, who said he grew up watching big-serving players like Boris Becker, Goran Ivanisevic and Pete Sampras, faces another Wimbledon great in Federer, the five-times champion, in the quarter-finals.

"I like those sort of challenges," said Federer when asked about the prospect of playing Karlovic. "He makes it hard on you to beat him.

"He's become an excellent player and it's not only just his serve."

Karlovic certainly looked good against Verdasco.

The Spaniard has a mighty serve himself but he could not compete with the imposing Karlovic, who took the first set 7-5 on a tiebreak before Verdasco levelled up, taking the second breaker 7-4.

It was not exactly subtle stuff and the only variation on the theme came in the third set when Verdasco went 0-40 in the eighth game and lost the last of the break points after thrashing a forehand long.

Karlovic served out before the fourth set reverted to type, with the Croat taking the inevitable tiebreak 11-9, as Verdasco spooned an easy forehand long.