No. 1-ranked Novak Djokovic is already into the third round, extending his winning streak at Melbourne Park to 16 with a 6-1, 6-2, 6-3 win over 20-year-old American Ryan Harrison.
He’s on track for a record third consecutive Australian Open title and doesn’t have any other major winners on his half of the draw after Rafael Nadal withdrew and Federer, Andy Murray and Juan Martin del Potro landed on the opposite side.
Djokovic will next play No. 31 Radek Stepanek, who beat Feliciano Lopez 6-2, 6-2, 6-4.
Fourth-ranked David Ferrer beat American Tim Smyczek 6-0, 7-5, 4-6, 6-3. No. 5 Tomas Berdych defeated Guillaume Rufin of France 6-2, 6-2, 6-4, and No. 8 Janko Tipsarevic took almost four hours to oust Lukas Lacko 6-3, 6-4, 3-6, 4-6, 7-5.
Among the other men advancing were No. 10 Nicolas Almagro, No. 16-ranked Kei Nishikori, No. 22 Fernando Verdasco and No. 20 Sam Querrey, who moved on when fellow American Brian Baker retired in the second set.
Baker, who returned to the tour last year after missing almost six seasons with various injuries, was pushed from Court 6 in a wheelchair with torn ligaments in his right knee.
‘‘He’s the last person that deserves anything like that with his five or six surgeries already,’’ Querrey said.