MELBOURNE, Australia (AP) The stark reality of an Australian Open third round without Novak Djokovic - for the first time in 11 years - hits home on Saturday when the remaining players in his half of the draw, Rafael Nadal and Milos Raonic among them, attempt to advance to the second week of the tournament.
Djokovic was beaten on Thursday in five sets by wild-card entry Denis Istomin, the earliest that the Serbian star has left Melbourne Park in singles since his first appearance here in 2006 when he was beaten by American Paul Goldstein in the first round.
''What Novak did here is just amazing, six victories here, six titles ... so it is not possible to be every time in that situation, no?'' Nadal said after his second-round win.
''So then today was probably an accident, that's all. We are athletes. We know when we are going on court we can lose and we can win. It probably was a combination that Denis played a great match and Novak didn't play his best. When this combination happens, then you are in trouble. Everything can happen. And (it) happened.''
Istomin, meanwhile, plays on. He's up against 30th-ranked Pablo Carreno Busta on Show Court 2 on Friday.
Here's a look at some of the key matchups Saturday:
RAFA'S TOUGH ASSIGNMENT: Nadal plays 19-year-old Alexander Zverev in an afternoon match at Rod Laver Arena. The young German was voted the ATP Star of Tomorrow in 2015 and has mostly lived up to the hype, seeded 24th here. ''He is one of the best players in the world, without a doubt ... and one of the next Grand Slam winners,'' Nadal said. ''He has a big chance to become the future world No. 1 if he's able to keep improving the way that he's doing.''
Nadal has been playing well since his return to the circuit after two lengthy injury spells last year, the 14-time major winner looking almost flawless in his straight sets win over Marcos Baghdatis in the second round.
Still, he's expecting to have his hands full with Zverev: ''I know I have a very tough match ... I know I need to play my best if I want to have a chance.''
A SERENA BREATHER?: Six-time Australian Open champion Serena Williams had two fairly tough matches through the first two rounds, facing Belinda Bencic, a former No. 7-ranked player now sitting at 59, and Lucie Safarova, ranked No. 61 but who Williams beat in the 2015 French Open final. Williams won both matches in straight sets. Her third-round match is against fellow American Nicole Gibbs, who Williams beat in straight sets at Stanford in 2012 in their only previous meeting. Williams said she feels she's better for the experience of having had tough opposition in the first two rounds. ''When I play players like Bencic and Safarova, they force me to play better,'' Williams said. ''It forces my game from the very first day to be at a high level. I needed something to start really fast. I'm not going to complain about it.''
CONTRASTING STYLES: Third-seeded Milos Raonic plays Gilles Simon on Hisense Arena and the Canadian holds a 3-1 edge in career meetings. Their only Grand Slam match came in the fourth round of the 2014 French Open, when Raonic won in five sets, including 7-5 in the fifth. ''I know a lot about his game. I've watched him play a lot,'' Raonic said. ''He's going to be there really trying to get me to play at his speed, his rhythm. Obviously he tries to slow things down, play low. I won't have the opportunity to get too many swings at many shots.''
Which means Raonic, with one of the best serves in the game, will try to get points over quickly.
''I've got to serve well and I've got to be aggressive and I've got to take it to him. The last thing I want to do is get into this sort of game of playing long rallies with him.''
KONTA vs WOZNIACKI: Last year's semifinalist Johanna Konta and Caroline Wozniacki, a former No. 1 who made it to the final four here in 2011, meet for the first time in an afternoon match at Margaret Court Arena. Both have been playing well, Konta coming off a win in the Sydney International last week, and Wozniacki having dropped just seven games in her first two matches at Melbourne Park. ''She had a good last year,'' Wozniacki said. ''But at the end of the day, it doesn't matter who is on the other side.''