ROME -- Denis Shapovalov needed fewer than 90 minutes to reach the second round of the Italian Open, while fellow Canadian Milos Raonic had to wait on Mother Nature before earning his chance to advance on Tuesday.

The No. 12-seeded Shapovalov, from Richmond Hill, Ont., beat world No. 37 Guido Pella of Argentina 6-2, 6-3 at the ATP Masters 1000 clay-court event. Later, No. 13-seeded Raonic defeated France's Adrian Mannarino 7-6 (3), 6-2 following a rain delay.

Shapovalov won 85 per cent of points when he got his first serve in (22 of 26), well above Pella's 62 per-cent clip (22 of 40).

Shapovalov will face world No. 109 Pedro Martinez, a qualifier from Spain, in the second round.

The 21-year-old Shapovalov is coming off a run to the quarterfinals at the U.S. Open.

Raonic, from Thornhill, Ont., was up 3-2 on world No. 38 Mannarino before play was halted due to rain. After a delay just short of an hour, Raonic won the first set via tiebreak before rolling to victory.

The Canadian had 12 aces compared to Mannarino's one. Raonic will square off against world No. 25 Dusan Lajovic of Serbia in the next round.

No. 16 seed Felix Auger-Aliassime of Montreal lost his first-round match to Serbia's Filip Krajinovic on Monday.

Meanwhile, Novak Djokovic's first match since being defaulted from the U.S. Open will come against local wild-card entry Salvatore Caruso in the second round.

The 87th-ranked Caruso defeated American qualifier Tennys Sandgren 3-6, 6-3, 7-6 (4) Tuesday in the opening round at the empty Foro Italico, where fans are being kept away because of the coronavirus pandemic.

Caruso saved a match point late in the third set before closing it out after nearly three hours on a steamy 32 C day.

The top-ranked Djokovic, who had a first-round bye, said Monday that he learned “a big lesson” after he was thrown out of the tournament in New York for unintentionally hitting a line judge in the throat with a ball.

Djokovic beat Caruso in straight sets in their only career meeting in the third round of last year's French Open.

“I'll try to draw from what I learned in that match,” Caruso said. “I'll try to take a set from him and, who knows, maybe even the match. I've got to go out onto the court with the mindset that I can win.”

Also on Rome's red clay, U.S. Open quarterfinalist Andrey Rublev of Russia eliminated Argentine qualifier Facundo Bagnis 6-4, 6-4.

Astralia's Alex de Minaur - another U.S. Open quarterfinalist - was tentative and wasted numerous chances in a 3-6, 6-3, 7-6 (6) loss to German qualifier Diminik Koepfer.

Also, Argentine qualifier Federico Coria, the younger brother of 2005 Rome runner-up Guillermo Coria, beat Jan-Lennard Struff 6-1, 7-6 (5). Coria will next face local favourite Matteo Berrettini, the No. 4 seed.

In the women's tournament, Katerina Siniakova rolled past three-time Grand Slam champion Angelique Kerber 6-3, 6-1; and last year's French Open finalist, Marketa Vondroušova, held off a comeback from Japanese qualifier Misaki Doi to win 6-1, 4-6, 6-4.

Also, Coco Gauff won her first Tour-level match on clay, sliding into her shots like a veteran in beating 34th-ranked Ons Jabeur 6-4, 6-3.

But the 16-year-old American also hit three consecutive double-faults to hand back an early break in the second set before regaining her composure to seal the victory in 1 hour, 21 minutes.

Gauff said she had good results on clay as a junior and noted that she spends a lot of time on the surface at the French academy run by Patrick Mouratoglu, Serena Williams' coach.

“I've been going there since I was 10,” Gauff said. “So I'm quite used to the red clay.”

- With files from The Associated Press.

This report by The Canadian Press was first published Sept. 15, 2020.