Roger Federer, Novak Djokovic, Rafael Nadal and Naomi Osaka all played and won twice at the Italian Open on Thursday in an extended schedule following Wednesday's postponement due to rain.
Federer beat Joao Sousa 6-4, 6-3 in his first appearance at the Rome Masters since 2016, before beating Borna Coric in three sets.
Djokovic saw off Denis Shapovalov and Philipp Kohlschreiber, Nadal gave up just one game apiece against Jeremy Chardy and Nikoloz Basilashvili, and Osaka downed Dominika Cibulkova and Mihaela Buzarnescu.
Meanwhile, Nick Kyrgios walked out of his match with Casper Ruud after throwing a chair onto the court.
There were upsets in both the men's and women's tournaments as No. 7 seed Sloane Stephens and Venus Williams both fell to Johanna Konta, while Simona Halep, Marin Cilic and Dominic Thiem were also knocked out.
Selected Monday Results
(1) Novak Djokovic bt. Denis Shapovalov: 6-1, 6-3
Jan-Lennard Struff bt. (9) Marin Cilic: 6-2, 6-3
(3) Roger Federer bt. Joao Sousa: 6-4, 6-3
Fernando Verdasco bt. (5) Dominic Thiem: 4-6, 6-4, 7-5
(2) Rafael Nadal bt. Jeremy Chardy: 6-0, 6-1
Casper Ruud bt. Nick Kyrgios: 6-3, 6-7 (5), 2-1 (Ret.)
(1) Novak Djokovic* bt. Philipp Kohlschreiber: 6-3, 6-0
(3) Roger Federer* bt. Borna Coric: 2-6, 6-4, 7-6 (7)
(2) Rafael Nadal* bt. Nikoloz Basilashvili: 6-1, 6-0
(1) Naomi Osaka bt. Dominika Cibulkova: 6-3, 6-3
(2) Petra Kvitova bt. Yulia Putintseva: 6-0, 6-1
(6) Kiki Bertens bt. Amanda Anisimova: 6-2, 4-6, 7-5
Johanna Konta bt. (7) Sloane Stephens: 6-7 (3), 6-4, 6-1
Marketa Vondrousova bt. (3) Simona Halep: 2-6, 7-5, 6-3
Garbine Muguruza bt. Danielle Collins: 6-4, 4-6, 6-2
Kristina Mladenovic bt. Belinda Bencic: 6-2, 2-6, 6-1
Johanna Konta* bt. Venus Williams: 6-2, 6-4
Kristina Mladenovic* bt. (8) Ash Barty: 6-2, 6-3
(1) Naomi Osaka* bt. Mihaela Buzarnescu: 6-3, 6-3
Full results and schedule can be found via the Pro Tennis Live app.
The action started earlier than usual in the Italian capital as organisers looked to make up time following a complete washout on Wednesday.
First on court was world No. 1 Osaka, who will be looking to win a third Grand Slam in succession at the French Open, which starts later this month.
She dispatched Cibulkova in one hour, 42 minutes to advance to the last 16.
The Japanese star lost an early break, but she came roaring back with some trademark big hitting.
She saved seven of eight break points conceded in the match, while taking four of the 15 she earned, and hit 44 winners and 12 aces.
Cibulkova simply could not live with Osaka, and the top seed eventually finished her opponent off in typical style:
Federer was similarly efficient in his match against Sousa. The Portuguese made Federer work hard for the victory, but the 20-time Grand Slam champion had more than enough quality to respond.
He took the opening set with a hold to love in 41 minutes, and as so often with Federer, it was his serve that saw him through.
The Swiss legend saved all seven of the break points Sousa earned, defending with some quite staggering play when put under pressure by his opponent:
And he won 77 percent of points behind his first serve to eventually grind Sousa into submission.
The 37-year-old was caught cold in the opening set of his second match, but he quickly responded to edge out Coric in the second and third sets.
Nadal's performance was brutal as he blew Chardy away in a little over an hour.
A quite ludicrous backhand passing winner from the Spaniard to seal the opening set 6-0 summed things up as Chardy simply could not get close to the eight-time winner and defending champion.
The Frenchman saved himself the embarrassment of a double bagel by holding once in the second set, but he understandably could not get off the court quick enough after Nadal sealed victory.
Nadal had a similarly straightforward time against Basilashvili.
The Spaniard was recently described as "salty" by Kyrgios on the No Challenges Remaining podcast of tennis writer Ben Rothenberg (h/t the Australian Associated Press, for the Guardian).
As Rothenberg observed, the Australian continued to make waves on Thursday:
Meanwhile, Djokovic is going for his third tournament win of the year after triumphs at the Australian Open and the Madrid Open, and he began his campaign in Rome in emphatic fashion.
The top seed was fast out of the blocks, earning two breaks in the first set to immediately get on the front foot and leave Shapovalov with a mountain to climb.
Serving at a remarkable 80 percent, the Serb won 28 points from 32 behind his first serve and did not concede a single break point.
Unable to produce a similar level of play with the ball in hand, the 20-year-old Shapovalov simply could not compete.
He served at 52 percent during the match and Djokovic took advantage as he completed his first victory of the tournament in 66 minutes.