Martina Hingis and Daniela Hantuchova were doubles teammates on the WTA Tour in 2013, and past losses to Hantuchova in singles burned in the Washington Kastles’ star’s memory. So when the Kastles and San Diego Aviators met in a World Team Tennis clash Monday night at Smith Center, Hingis — who often plays with a smile that seems painted on — was dead-serious against San Diego’s Hantuchova.

The singles set offered Hingis a chance for revenge, but she was unable to take advantage as she and the Kastles fell, 22-18, snapping an 18-match winning streak.

Hingis and Hantuchova last met in singles in 2007 with Hantuchova winning both matches against Hingis that year.

“I don’t really have a winning record against her, so I had to take it seriously,” Hingis said. “Every point counted.”

Hantuchova took an early 2-0 lead in the set. Hingis won the next two games, but Hantuchova won three straight games to close out the match. Hingis entered Monday’s match having won 20 of her 22 games in team tennis women’s singles sets this season.

They played doubles together in the 2007 U.S. Open, losing in the round of 16 to Rennae Stubbs and Kveta Peschke, now a member of the Aviators. When Hingis was mulling a return to the WTA doubles circuit, Hantuchova encouraged her and suggested the two pair up.

They parted ways after they lost three of the five matches they played together in 2013, but the two remained good friends. Hantuchova has said Hingis was her idol growing up.

“It’s always so much fun playing against her,” Hantuchova said. “I always feel like she brings the best out of me when I play against her.”

The Aviators took a 17-14 lead into men’s doubles, the final set of the match, and won it in a tiebreaker to take the set and match.

The Kastles had won by at least eight games in their matches this season entering Monday’s match, but the Aviators, the top team in the Western Conference, won the first two sets, winning men’s singles, 5-4, and women’s doubles, 5-3.

Hingis and Leander Paes are undefeated together in mixed doubles since the start of last season, and the duo got out to an early 3-0 lead in the set to tie the match at 10. But San Diego’s duo of Peschke and Raven Klaasen won the next two games to reclaim the Aviators’ lead in the match. Paes and Hingis won the next two games, setting up a tiebreaking match for Hingis’s set against Hantuchova.

“She came out with her best tonight against me,” Hingis said. “Hopefully, I get another chance at her.”