MIAMI GARDENS, FLA. -- Bianca Andreescu of Canada -- the 2019 U.S. Open champion -- beat 2020 Australian Open winner Sofia Kenin of the United States 6-4, 6-4 in the third round of the Miami Open on Sunday.

Andreescu advanced to the tournament's fourth round for the third time. She had seven aces to Kenin's one, and double-faulted only once as she won the third straight matchup between the Grand Slam champions. Andreescu converted all three of her break opportunities.

In other matches, Australian Open winner and world No. 2 Aryna Sabalenka of Belarus defeated Marie Bouzkova of the Czech Republic 6-1, 6-2; and Barbora Krejcikova of the Czech Republic outlasted American Madison Keys 7-6 (4), 6-3.

Also, Ekaterina Alexandrova of Russia defeated world No. 9 Belinda Bencic of Switzerland, the gold medalist at the Tokyo Olympics, 7-6 (8), 6-3; Marketa Vondrousova ousted Karolina Pliskova 6-1, 6-2 in an all-Czech matchup; Sorana Cirstea of Romania beat Karolina Muchova of the Czech Republic 7-5, 6-1; and Varvara Gracheva of Russia defeated Magdalena Frech of Poland 6-1, 6-2.

On the men's side, Botic van de Zandschulp of the Netherlands outlasted world No. 4 Casper Ruud of Norway 3-6, 6-4, 6-4.

Van de Zandschulp had 12 aces to Ruud's six, but they each had three double-faults. Van de Zandschulp will face Emil Ruusuvuori of Finland in the next round.

World No. 1 Carlos Alcaraz of Spain beat Dusan Lajovic of Serbia 6-0, 7-6 (5). Alcaraz faces American Tommy Paul on Tuesday.

"Yeah, today has been a great match, great level. I hope to play at this level on Tuesday," Alcaraz said. "I lost the first and only match that I played against Tommy. I know that he's a really talented and really tough player, so I have to play at my best. Let's see what's going to happen on Tuesday."

Paul and fellow American No. 10 Taylor Fritz advanced in straight sets.

Paul beat Alejandro Davidovich Fokina of Spain 6-3, 7-5, helped by eight aces. Fokina had six double-faults.

Fritz defeated Denis Shapovalov of Canada 6-4, 6-4. Shapovalov had seven double-faults. Fritz will face world No. 8 Holger Rune of Denmark, who defeated Diego Schwartzman of Argentina 6-4, 6-2.

"It's going to be a tough match I think for a round of 16," Fritz said. "Myself playing Holger is a very tough draw. I'm excited to play him. We've never played before. I'm not entirely I guess sure what to make of his game. Obviously he's very good."

Also, Andrey Rublev of Russia dispatched Miomir Kecmanovic of Serbian 6-1, 6-2.