MELBOURNE, Australia (AP) -- For a full two sets and nine games, Roger Federer was the picture of poise, picking up half-volleys with vintage panache and placing winners past Andy Murray.
Then, in the bounce of a ball -- or two bounces of the ball, depending on opinion -- the 17-time major winner was transformed back into the vulnerable, 2013-edition Federer.
After breaking Murray to get a chance to serve for the match on Wednesday and a spot in the Australian Open semifinals for an 11th consecutive year, Federer dropped serve.
He recovered and jumped to a 5-2 lead in the tiebreaker, but then Murray rallied and won six of the last seven points to prolong the quarterfinal.
After wasting a handful of break-point chances in Murray’s next service game, which lasted almost 19 minutes, Federer finally wore down the Wimbledon champion 6-3, 6-4, 6-7 (6), 6-3 to set up a semifinal showdown with top-ranked Rafael Nadal.
"For me it was just a matter of staying calm and forgetting about it a little bit because, you know, the match was great until that point," Federer said.
Murray made his resurgence after disputing a point in the ninth game of the third set, when he thought the ball had bounced twice before Federer hit it. Replays shown in Rod Laver Arena were inconclusive. Federer thought was good, and left the call to the umpire.
Nadal lost the first set and faced set points in the third, getting a reprieve when first-time quarterfinalist Grigor Dimitrov pushed a forehand just wide in a tiebreaker. Despite a painful blister on the palm of his left hand that hampered his serve, Nadal advanced 3-6, 7-6 (3), 7-6 (7), 6-2 against the 22-year-old Bulgarian.
And that’s how the greatest of modern day champions reconcile it. On a day when two-time defending Australian Open champion Victoria Azarenka lost 6-1, 5-7, 6-0 to No. 5 Agnieszka Radwanska and following other stars out of the tournament, Nadal and Federer won back-to-back matches on center court to set up their 33rd showdown.
Stan Wawrinka ended Novak Djokovic’s bid for a fourth straight Australian Open title with an upset win in the quarterfinals and will face 2010 Wimbledon finalist Tomas Berdych in the semifinals on Thursday. Neither has won a Grand Slam title, but one is guaranteed to get a chance in Australia.