Seven-time champion Rafael Nadal methodically wore down Denis Shapovalov 6-4, 6-1 Thursday to reach the Italian Open quarterfinals and gain revenge against the Canadian teenager.
The 19-year-old Shapovalov stunned Nadal in the third round in Montreal last year to deny the Spanish player a chance to regain the No. 1 spot.
Nadal is also attempting to win the top spot back this week. He'll replace Roger Federer if he wins an eighth Rome title.
In a match between two left-handers, Shapovalov saved eight break points in his opening two service games before finally dropping his serve midway through the first set.
"He was really serving big and I had some mistakes with the return," Nadal said. "It was not a comfortable match against a lefty who serves big and goes for his shots.
"He's good in all aspects. The only thing he needs is a little bit more time."
Shapovalov was stretched to three sets in his opening two matches, against 15th-seeded Tomas Berdych and Robin Haase, and reached the semifinals of last week's Madrid Open.
"I didn't feel completely dead out there but I felt like I could've been fresher," Shapovalov said.
Nadal, who hasn't won the Italian Open since 2013, next faces Fabio Fognini, who beat Peter Gojowczyk 6-4, 6-4.
Fognini slammed his racket midway through the second set and received a warning from the umpire but otherwise held his composure to follow up an impressive win over Dominic Thiem.
Defending champion Alexander Zverev, seeded second, is also through to the quarterfinals, but Brit Kyle Edmund put up quite a fight.
In a thrilling second set tiebreaker, Edmund saved seven match points before eventually succumbing the the German, who took the match 7-5, 7-6 (11).
Fourth-seeded Marin Cilic defeated Benoit Paire 6-3, 6-4 while ninth-seeded David Goffin was leading 6-2, 4-5 when Juan Martin del Potro retired because of a groin injury.
Cilic will play 10th-seeded Pablo Carreno Busta, who beat Aljaz Bedene 6-4, 6-7 (3), 6-2.
In the women's tournament, Simona Halep's hold on the No. 1 ranking received a boost when American Madison Keys withdrew from their last-16 match due to a rib injury.
Halep now needs to progress further than No. 2 Caroline Wozniacki to stay in top spot.
Wozniacki faces 15th-seeded Anastasija Sevastova in a late match.
The winner will play Anett Kontaveit, who ousted 1999 champion Venus Williams 6-2, 7-6 (3).
Last year, Halep rolled her ankle in the final and lost a lead and the championship to Elina Svitolina.
Halep next plays U.S. Open champion Sloane Stephens or seventh-seeded Caroline Garcia.
Svitolina overcame a poor start to beat 14th-seeded Daria Kasatkina 0-6, 6-3, 6-2. She'll next face former No. 1 Angelique Kerber, who routed Maria Sakkari of Greece 6-1, 6-1.
This is the last major warmup for the French Open, which starts in 10 days.
Jelena Ostapenko, preparing to defend her title at Roland Garros, rallied past Johanna Konta 2-6, 6-3, 6-4 and will meet three-time Rome champion Maria Sharapova or Daria Gavrilova.