Nick Kyrgios of Australia captured the Citi Open in Washington, D.C., for the second time with a 6-4, 6-3 win over Yoshihito Nishioka of Japan on Sunday.

Kyrgios, who also won the event in 2019, powered 12 aces compared to just three for Nishioka. Kyrgios, who made it to the final at Wimbledon before losing to Novak Djokovic last month, broke Nishioka's serve in the first game of the match and never game him a chance to get back in the set.

Kyrgios then broke Nishioka's serve to begin the second set and again went on to win the match.

Kyrgios, who dealt with mental health issues last year, said the win was "very emotional."

"To see where I was at last year to now, it's just an incredible transformation. I just came out with great energy. I knew that I had experience on my side today. I love this court, I've played so many good matches here, so I'm just really happy with myself," he said after the match.

National Bank Open

No. 1 Marcos Giron of the United States defeated No. 13 Alexei Popyrin of Austrailia in three sets to earn a berth in the round of 64 in Montreal. Giron emerged with a 6-4, 6-7 (10), 6-1 win on Sunday, and will face Spain's Roberto Bautista Agut, the 14th seed, on Monday.

Benoit Paire of France qualified by beating Marc-Andrea Huesler of Switzerland 6-3, 3-6, 6-1.

Other winners Sunday included Frenchmen Adrian Mannarino and Arthur Rinderknech, who will face each other in the round of 64. Mannarino is ranked fifth, while Rinderknech is sixth.

Second-seeded Fabio Fognini of Italy won his qualifier and will take on Holger Rune of Denmark on Monday. France's No. 8 Hugo Gaston will meet No. 11 Jack Draper of Great Britain in the round of 64 on Monday after both won their qualifying matches.