STUTTGART • Roger Federer is one win away from reclaiming tennis' world No. 1 spot from Rafael Nadal, following his 6-4, 6-4 win over Argentinian Guido Pella in the Stuttgart Open quarter-finals yesterday.
The Swiss will next face either Australian Nick Kyrgios or Spaniard Feliciano Lopez. Their match did not end by press time.
If Federer prevails and reaches the final, the 36-year-old will then be atop the rankings for the third time this season even if he does not win the tournament.
It was the 19th win for Federer from 21 matches this year and his 166th in total on grass, a boost for the Swiss ahead of next month's Wimbledon Championships.
Federer is a 20-time Grand Slam champion and he won his sixth Australian Open this year.
He may still be going strong but, at 36, he hinted that he may need to start thinking about retirement.
"The most important thing, first of all, is the joy of the game," he said, as quoted by the Metro newspaper.
"And to prove to myself and my team that I can win another tournament or defend a title.
"Of course, it would be nice to become No. 1 again and turn this record upwards. The end is closer then ever before. But I also do not know when it's over."
In the other quarter-finals, Canadian Milos Raonic reached his second semi-final of the season to set up a clash with defending champion Lucas Pouille, who beat Uzbek Denis Istomin 6-4, 6-7 (5-7), 6-3.
Raonic used his big-serving game to dominate a pair of tie-breakers in a 7-6 (7-2), 7-6 (7-1) win over Tomas Berdych of the Czech Republic.
"I got fortunate in the tie-breakers," the 27-year-old seventh seed said after reaching his first semi-final since Indian Wells in March.
"He gave me some points at the start of both tie-breaks and I was able to keep myself disciplined on serve to win them.
"I like this court, the speed is good for me, there are no bad bounces and it's holding up well."