Sabalenka beats Azarenka to reach Washington Open semis

Aryna Sabalenka withstood a shaky second set to defeat Victoria Azarenka 6-4, 6-4 in a Friday showdown of two-time Australian Open champions to reach the Washington Open semi-finals.

Third-ranked Sabalenka fired eight aces in the matchup of Belarus rivals at the WTA and ATP hardcourt tuneup for the US Open.

"Always tough battles against her," Sabalenka said. "She always brings the best fight she can. I always enjoy playing against her. Just super happy to get through this tough match.

"I feel like with every set, I play better and better. Hopefully I can just (keep) building my level and by the US Open, I'll be 100 percent ready."

Sabalenka, who won her second consecutive Australian Open in January, and 20th-ranked Azarenka both withdrew from Wimbledon with shoulder problems but have shown no sign of injuries in the US capital this week.

"I'm super happy. I'm doing really great so far. Fingers crossed, the injury's in the past. I feel really good," Sabalenka said.

"We're doing everything we can with my team to keep my shoulder strong and make sure (such an injury) will never happen again."

Top seed Sabalenka advanced to a Saturday semi-final against Czech Marie Bouzkova, who beat 19-year-old American Robin Montgomery, 6-3, 6-1.

Sabalenka won their only meeting last year in Miami, dropping only three games.

"Even though the score was quite easy in our last meeting, it was a really tough battle. It wasn't that easy as it looks," Sabalenka said. "She's a great fighter."

Sabalenka, 26, improved to 5-1 against Azarenka, 35, in WTA clashes with her fourth consecutive triumph, all in straight sets.

Azarenka swatted a backhand long to give Sabalenka a break and a 4-2 lead but three double faults in the seventh game by Sabalenka handed a break back.

Azarenka sent a forehand beyond the baseline to surrender a break in the 10-minute 10th game and drop the first set in 52 minutes.

In the second set, Azarenka double faulted away a break in the second game, but Sabalenka did the same in the fifth game.

On Sabalenka's first match point, Azarenka double faulted to end matters after an hour and 46 minutes.

Sabalenka connected on only 18 of 40 first serves (45%) in the second set but won 10 of 22 second-serve points to Azarenka's 3 of 10.

- Shelton wins on default -

On the men's side, world number eight Andrey Rublev faced hometown hero Frances Tiafoe in the last quarter-final.

The winner will advance to face US fourth seed Sebastian Korda, who eliminated Australian seventh seed Jordan Thompson 6-4, 6-2.

US second seed Ben Shelton had three match points in a second-set tie-breaker when Denis Shapovalov began shouting at a spectator and the Canadian wild card was defaulted for unsportsmanlike conduct, Shelton winning 7-6 (7/5), 6-6.

"It's unfortunate that a high-level match like that, such a great match that was highly contested, just an all-out war, ended like that," said Shelton. "You never want to see it."

Shelton reached a semi-final against Italian 10th seed Flavio Cobolli, who outlasted American Alex Michelsen 7-5, 3-6, 7-6 (7/2) after two hours and 39 minutes.

The other women's semi-final will send Spain's Paula Badosa against American Caroline Dolehide.

Badosa rallied past Britain's Emma Raducanu 4-6, 7-5, 6-4 in two hours and 45 minutes, while Dolehide downed compatriot Amanda Anisimova 7-6 (7/5), 6-1.