Before each day of play at the Australian Open, we'll preview and predict three must-see matches. For full coverage of the season's first Slam, go to our tournament page.

This is a “something has to give” type of fourth-rounder: Wawrinka and Raonic both began the season with titles (Stan in Chennai, Milos in Brisbane), and neither has dropped a set in his first three matches at Melbourne Park. Based on form, it’s hard to go against Raonic, who is hitting his forehand as well as he has ever hit it. But based on history, it’s even harder to go against Wawrinka. He won the title here two years ago, and in his four previous matches with Raonic, he’s dropped just one set.

Winner: Wawrinka

Whenever you need someone to send a young upstart out of your tournament, call Murray. His supple-wallboard style tends to confuse inexperienced and emotional players—just ask Nick Kyrgios (at last year's U.S. Open and Australian Open) and Alexander Zverev (a few days ago in Melbourne). At 23, Tomic is not exactly inexperienced, but judging by his comments about Roger Federer this week, he’s still an upstart. More important, he’s still flummoxed by Murray, who hasn’t dropped a set to Tomic in three meetings.

Winner: Murray

Before she arrived in Melbourne, the 27-year-old Zhang hadn’t won a Grand Slam match. Now she’s won three qualifying rounds and three main-draw rounds without dropping so much as a set—and one of those victories came over the No. 2 seed, Simona Halep. For those efforts, the 133rd-ranked Zhang will get a chance to play a night match in Rod Laver Arena. Can she keep her Cinderella streak alive? That will depend on how Keys, last year’s Cinderella in Oz, is hitting the ball. They split their previous two matches.

Winner: Keys