ROME, 16 September 2020 (TON): Italian teenager Lorenzo Musetti upset three-time Grand Slam champion Stan Wawrinka 6-0, 7-6 (2) in the first round of the Internazionali BNL d'Italia on Tuesday for his first ATP Tour triumph.

The 18-year-old Musetti lost his only previous tour-level match before stunning the 10th-seeded Swiss veteran on the clay courts of Rome in one hour and 24 minutes.

"First set was almost perfect. Second set he tried to play better," Musetti said. "He was focused on the match and he wanted to win the set, but I served really good. ... I think the serve was the key."

Musetti tallied five aces and zero double faults and won 69 percent of his first-service points in a matchup of the tournament's youngest and oldest players.

After losing the first eight games of the match, the 35-year-old Wawrinka overcame an early break in the second set to get back on serve.

Musetti, ranked No. 249 in the world, finished off his victory in the tiebreak with a cross-court forehand passing shot. He became the first player born in 2002 to win a match on the ATP Tour.

He will face Japan's Kei Nishikori in the second round.

"I have seen him play on television and I know he is a very tough player," Musetti said. "I'm going to enjoy the victory before I start thinking about my match against Nishikori."

In other action Tuesday, No. 9 seed Andrey Rublev of Russia posted a 6-4, 6-4 win against Argentina's Facundo Bagnis. Rublev struck 25 winners in his 20th match win of the season.

No. 12 seed Denis Shapovalov of Canada hit 23 winners and won 12 of 15 points at the net in a 6-2, 6-3 victory against Argentina's Guido Pella.

No. 13 seed Milos Raonic of Canada advanced with a 7-6 (3), 6-2 win against France's Adrian Mannarino. Raonic smashed 12 aces, won 29 of his 31 first-service points and never faced a break point.

Other winners included Japan's Yoshihito Nishioka, Serbia's Dusan Lajovic, Spain's Pedro Martinez, Italy's Salvatore Caruso and Marco Cecchinato, Germany's Dominik Koepfer, Argentina's Federico Coria and Australia's John Millman.

Caruso will face top seed and four-time Rome champion Novak Djokovic of Serbia in the second round.

Millman rallied from 2-4 down in the second set to defeat Joao Sousa 7-5, 7-6 (2) in two hours and four minutes.