Roger Federer's grip on the No. 1 ranking weakened as No. 16 seed Ivo Karlovic defeated the Swiss 7-6(6), 4-6, 7-6(5) in the third round on Thursday.
Federer, who has been No. 1 in the South African Airways ATP Rankings for a record 235 weeks (since Feb. 4, 2004), will lose the top ranking if No. 2 Rafael Nadal wins the title. Federer has 6,680 points after his third round loss and Nadal will have 6,730 points if he captures the tournament crown.
Federer lost the two hour and 10-minute match without dropping serve and losing to the big-serving Croat for the first time in seven meetings.
"Well, I mean, it's disappointing losing without getting broken, but it's not the first player it happens to," said Federer, who lost for the first time in his career without getting broken. "You know, especially against a guy like Ivo. He served really well, so it was always going to be a hard match. A couple points here and there really made the difference. I mean, I don't know where and when they were, but he got the upper hand in the end."
Karlovic, who came in with an 1-8 mark in his career in tie-breaks against Federer, won the opening tie-break 8-6 as neither player faced a break point in the set. In the second set, Federer broke in the fifth game and went on to level the match.
"I knew that he cannot win always the tiebreaks, because it is some kind of lottery," said Karlovic, who fired 22 aces. "So I was focused, and I served well and I won."
In the third set, neither player lost more than two points on serve in a game. Federer fell a mini-break down at 0-2 in the tie-break on a backhand error and trailed throughout. Federer saved two match points on his serve at 3-6 before the Swiss hit a backhand return long on Karlovic's second serve.
"He didn't have a lot of unforced errors and he was playing well from the baseline, and I had almost no chance to break him," said Karlovic who has broken Federer once in seven career meetings. "So I think that he was playing on the same level as before."