Serena Williams weathered a barrage of big serves and heavy groundstrokes in the first set before beating 19-year-old Madison Keys to set up an Australian Open final against Maria Sharapova.
Novak Djokovic reached his 25th Grand Slam semifinal by beating No. 8 Milos Raonic, 7-6 (5), 6-4, 6-2 at the Australian Open on Wednesday.
Rafael Nadal is out of the Australian Open, beaten 6-2, 6-0, 7-6 (5) in the quarterfinals by seventh-seeded Tomas Berdych on Tuesday.
Stan Wawrinka stayed in contention for a second consecutive Australian Open title with a 7-6 (2) 6-4, 4-6, 7-6 (8) win over Guillermo Garcia-Lopez on Monday to advance to the quarterfinals.
Federer was trying to come from two sets down for the 10th time in his career, most recently at last year’s U.S. Open against Gael Monfils.
Rafael Nadal persevered through stomach cramps to fend off American qualifier Tim Smyczek 6-2, 3-6, 6-7 (2), 6-3, 7-5 in a second-round match Wednesday at the Australian Open.
Andy Murray has beaten Roger Federer for the first time in a Grand Slam event to advance to the Australian Open final against top-ranked Novak Djokovic.
Golf officials are investigating a fight between two caddies near the practice chipping area at The Lakes before the first round of the Australian Open.