Once he'd become the first man to win 20 Grand Slam singles titles, the questions to Roger Federer shifted to another major milestone

Roger Federer has won his 20th Grand Slam singles title with a 6-2, 6-7 (5), 6-3, 3-6, 6-1 victory over Marin Cilic in the Australian Open final

Winning the Australian Open final gave Caroline Wozniacki her first major title, and a bonus prize

A look at what happened Sunday at the Australian Open

Roger Federer has captured his 20th Grand Slam singles title, beating Marin Cilic in a back-and-forth Australian Open final 6-2, 6-7 (5), 6-3, 3-6, 6-1

Roger Federer beats Marin Cilic in Australian Open final to win 20th Grand Slam title

Mate Pavic picked up two Grand Slam titles within 24 hours after winning the Australian Open mixed doubles on Sunday

Simona Halep is proud of her new aggressive game, mentality despite 3rd major final defeat at Australian Open

Caroline Wozniacki has won her first Grand Slam singles title in her 43rd major, beating top-seeded Simona Halep 7-6 (2), 3-6, 6-4 in the Australian Open final

A look ahead to the Australian Open for Sunday, and a Saturday recap