No.27 seed Marie Bouzkova of the Czech Republic notched an upset in a rain-postponed match at the Internazionali BNL d'Italia on Sunday, ousting No.6 seed Coco Gauff of the United States 4-6, 6-2, 6-2 to reach the Round of 16.

Bouzkova grabbed her third career Top 5 win -- and her first of those on clay -- with the 2-hour and 8-minute victory over World No.5 Gauff. Their match was originally scheduled for a Saturday-night showdown on Center Court before rain pushed it to Sunday.

Words from the winner: "Even after the first set, I just kept on fighting, and I kind of knew that I had to elevate my game to get the win today, and at least stay in the match," Bouzkova said afterwards. "I think I did that pretty well, and then my service games started to work, and I just started to feel really comfortable on the court.

"I love to play here. I think in Europe, it might be my favorite tournament. I didn’t play here last year, so I was really looking forward to playing here. I like the conditions and I like the crowd here, it gives me so much energy."

Kudermetova awaits: Bouzkova moves on to Monday’s Round of 16, where she will meet No.11 seed Veronika Kudermetova for the first time this season. They have split their four previous meetings overall.

"I expect a tough match, [Kudermetova is] a big hitter," Bouzkova said. "I just have to grind it out like I did today, fight for every ball, and let’s see what happens tomorrow."

Match breakdown: On Sunday, Bouzkova withstood six aces from Gauff on her way to victory. The Czech was impeccable on serve after the first set -- she never faced a break point in either the second or third set.

After the loss of a topsy-turvy opening set, Bouzkova took control of the second set with a gritty break for 3-1 on her sixth break point of that game. Bouzkova won 80 percent of her service points to take that set.

In the third set, Bouzkova cracked the match open by firing a backhand passing winner into the corner to break for a decisive 4-2 lead. Bouzkova reeled off the last four games to complete the upset.

Keys advances after injured Azarenka withdraws

The other third-round match in the bottom half that was postponed from Saturday night never started on Sunday. No.19 seed Madison Keys advanced into the Round of 16 via walkover, after No.14 seed Victoria Azarenka withdrew from their match due to a right leg injury.

Azarenka's injury also forced her out of this fortnight's doubles draw. She and partner Beatriz Haddad Maia won the Madrid title last week, in their first event as teammates.

American Keys, a Rome finalist in 2016, will meet No.30 seed Anhelina Kalinina of Ukraine in the Round of 16 on Monday. Kalinina and Keys faced off twice last year, and Kalinina won both of those meetings, including in the second round of Rome.