Alexei Popyrin upsets defending champion Andrey Rublev at Monte Carlo

Defending champion Andrey Rublev made an early exit, losing his opening-round match to Alexei Popyrin 6-4, 6-4 on Wednesday at the Rolex Monte Carlo Masters in Monaco.

Popyrin of Australia needed only one hour and 40 minutes to oust the Russian, ranked No. 6 in the world and defending his first ATP Masters 1000 crown.

"I enjoyed coming out on center court for the first time," Popyrin said of Court Rainier III. "First tournament on clay of the year and I have good memories from clay last year (a win in Umag). I am feeling really comfortable on it and happy to beat a guy who was in form, confident and the defending champ. It was an awesome match."

Popyrin recorded 25 winners, to 17 for the sixth-seeded Rublev, and converted 3 of 8 break-point opportunities, to 1 of 6 for his opponent.

"The idea was not to give him the same ball," Popyrin said. "He is probably the best player from the baseline when you give him rhythm, so I tried to change the pace, height and spin and I think it worked really well for me today."

Popyrin advanced to the third round against fellow Australian Alex de Minaur. The 11th-seeded de Minaur defeated Tallon Griekspoor of the Netherlands 2-6, 6-2, 6-3 in the Round of 32. It's the first time an Australian has reached the third stage in Monte Carlo since Lleyton Hewitt and Wayne Arthurs in 2004.

Second seed Jannik Sinner of Italy turned in a dominant 6-1, 6-2 effort against unseeded American Sebastian Korda in 75 minutes to reach the third round. Sinner, ranked No. 2 in the world, saved all three break points and won 95.2 percent (20 of 21) of points on his first serve.

"I think me and Sebi have similar game styles, so we are not playing like the classic clay-court specialists; we like to play quite flat," Sinner said. "But I moved quite well in these conditions. Every year it is tough to come here and perform well, but I am happy with the performance. Let's see what is coming in the next round."

Sinner will face Jan-Lennard Struff of Germany in the next round.

In other action Wednesday, fourth-seeded Daniil Medvedev of Russia ousted French wild card Gael Monfils 6-2, 6-4; eighth seed Casper Ruud of Norway won in straight sets over Alejandro Tabilo of Chile 6-2, 6-4; and 10th seed Hubert Hurkacz of Poland outbattled qualifier Roberto Bautista Agut of Spain 7-5, 7-6 (4).

Other winners were 12th seed Stefanos Tsitsipas of Greece, 14th seed Ugo Humbert of France, 15th seed Karen Khachanov of Russia and lucky loser Lorenzo Sonego of Italy.

Rain suspended play later Wednesday with seventh seed Holger Rune of Denmark leading India's Sumit Nagal 6-3, 2-1; and ninth seed Grigor Dimitrov of Bulgaria up 6-4, 2-1 against Miomir Kecmanovic of Serbia.