Karlovic's peak proves beyond limited climbing skills of Safin

When you have been scaling Himalayan peaks, confronting a 6ft 10in man mountain might not seem too daunting a challenge. Ivo Karlovic, however, is in a rich vein of form and the tallest player on the men's tour needed less than an hour at the Madrid Masters here yesterday to dispose of Marat Safin, who returned recently from an expedition to climb the world's sixth highest mountain.

Not even the thin air of Europe's highest capital – Madrid is 646 metres above sea level – could help the 27-year-old Russian as he lost 6-3, 6-4 under a barrage of aces from Karlovic, who claimed his third title of the year in Stockholm on Sunday. It continued an indifferent season for Safin, who reached the third round at the Australian Open and Wimbledon but has failed to win more than one match at any other Grand Slam or Masters series event in 2007.

The former world No 1 has always been one of the tour's more unpredictable characters and when a wrist injury put him out of action after the US Open he took the opportunity to join some friends setting out to climb Cho-Oyu, an 8,201m mountain on the border between Nepal and Tibet. At the time he said he hoped the experience would "renew my resolve and my powers for tennis".

Safin scaled a 4,100m peak as part of the acclimatisation process, but when the expedition moved to base camp to begin their assault on Cho-Oyu, which would have taken a month to climb, he decided to return home. It took him five days to climb back down the mountain and return to Moscow.

"I was there for less than two weeks," Safin said. "It was a good time to decide to come back. The conditions are really tough for someone who is doing it for the first time. The second time it will be easier."

He added: "I thought it was a good time to go. It was a great experience. Next time I decide to go I will be better prepared. Maybe next year."

When asked what he had gained from the experience, Safin replied: "It's hard to explain with words. You have to be there to understand how it feels." He said he felt "rejuvenated as a person as well as a player" and quoted a Russian proverb: "It's better to see one time than to hear 100 times."

Safin won the US Open in 2000 and went to the top the world rankings the following year, but his career has been punctuated by injuries and he has not won a tournament since beating Lleyton Hewitt in the Australian Open final in 2005. His best performance this year was a run to the semi-finals in Las Vegas in February.

This was his second tournament back after returning from Kathmandu. He played in the Kremlin Cup in Moscow last week, beating Denis Matsukevitch, the world No 422, before losing to Igor Andreev in the second round.

"My aim for this season is just to finish the year, that's it," he said after his latest defeat. "I don't know where I will play next as I need to ask for a wild card. I just want to finish the year and start slowly preparing for 2008."

Karlovic, who now meets another Russian in Nikolay Davydenko, is one year older than Safin, but his career is heading in the opposite direction. This was the Croat's ninth win in his last 10 matches and he has climbed to a career-high No 24 in the world rankings. Roger Federer is the only other player who has won on three different surfaces this year.

Yesterday's tally of 17 aces took Karlovic's total for the year to 1,152. Only one player has ever hit more in a single season, Karlovic's fellow countryman Goran Ivanisevic having done so in 1996 and 1994, with 1,477 and 1,169 respectively. No wonder Britain were grateful that Karlovic did not play in last month's Davis Cup tie at Wimbledon because of a dispute with the Croatian federation.