Heavy downpours suspended opening day play on the outer courts at the Australia Open, but a lot of the action played out under the roofs. Here are the Top 5 photos from Monday. (All photos from Getty Images.)
In their second career meeting, Coco Gauff beat Venus Williams, 7-6 (5), 6-3 (she also won their Wimbledon opener). Gauff, who at 15 is the youngest player in the draw, will take on Romanian Sorana Cirstea in the Australian Open second round.
Roger Federer opted to not play in the inaugural ATP Cup and didn't compete in any warm-up tournaments, but he looked to be in fine form on Monday. He eased passed American Steve Johnson, 6-3 6-2 6-2, in front of his family, including both sets of twins.
Rain hit Melbourne and suspended much of the event's first-round play. Hours after Day 1 kicked off, umbrellas went up and fans scurried to find somewhere dry to hide. The Grand Slam now faces the prospect of backlogged matches, but the wet weather is a huge relief for the bushfires.
Grigor Dimitrov suffered a shaky first set to defeat Juan Ignacio Londero, 4-6, 6-2, 6-0, 6-4. The No. 18 seed, who reached the Australian Open semifinals in 2017, will next face the winner of Tommy Paul and Leonardo Mayer.
Naomi Osaka had a great day at the office by defeating Marie Bouzkova in straight sets to start her title defense. She lost just six games, and heads into her second-round match against Zheng Saisai in confident form.