Alycia Parks showed that even though Serena Williams is retired, the Serena effect in U.S. tennis will live on

WATCH: Parks scores her first career Top 10 win, over Maria Sakkari

During her three-set upset win over Maria Sakkari in Ostrava this week, Atlanta native Alycia Parks made a gesture that would give any long-time tennis fan—and especially any long-time Serena Williams fan—a jolt of déjà vu.

Parks had lost the previous point. Just before starting her service motion on the next one, she put the palm of her left hand out, and gently pushed downward with it. The message to herself was: Stay calm; keep a level head. It’s the same gesture that Serena made, in exactly those stressful situations, for the better part of the last two decades.

Parks, 21, knows how to impersonate Serena. She has served as body double for Williams in Gatorade commercials in the past, and with her win over Sakkari, she joined Serena as the only WTA player outside the Top 100 to beat a Top 10 opponent this season. But there’s also more than a little of Serena’s sister Venus in the 6-foot-1 Parks’ game. Last year at the US Open she bombed in a serve at 129 m.p.h., matching Venus’ tournament record for a woman. Which isn’t a surprise. By the time she was 13, Parks had already hit a serve 113 m.p.h.

“Serena called me when I was 7 or 8,” Parks told The Palm Beach Post when she was 18 and starting her pro career. “She was saying positive things and telling me to stick with it. Now that I’m here, I’m sure she’s proud.”

“I pattern myself after Serena because of her serve, but I also like Venus’ movement.”

Parks’ young career carries echoes of the Williams sisters, as well as another of their successors, Coco Gauff. Like Serena, Parks has an older sister, Mikayla, and a father, Michael, who has coached them. Like Gauff, Alycia was born in Atlanta before moving to Delray Beach, Fla., and finally landing in Port St. Lucie.

Unlike Gauff and the Williamses, Parks didn’t have success at the highest level as a teenager. Until this week, her progress had been more gradual: One ITF-level title, and five runner-up finishes. In February, she took Wimbledon semifinalist Tatjana Maria to three sets in the final of a $60,000 event in Rome.

All of that changed over the past seven days in Ostrava. The tournament had a loaded field, but the young American buzzed through it and made herself the story of the week. On Tuesday, she beat former No. 1 Karolina Pliskova in two sets; on Thursday, she beat seventh-ranked Maria Sakkari in three; and on Friday, she pushed former No. 2 Barbora Krejcikova to a first-set tiebreaker before falling 7-6 (7), 6-3.

“I came out here not expecting anything, just playing my game, and it got me through the match,” Parks said after beating Sakkari. “I was coming from [clay courts in] Parma last week, and everyone said, ‘How are you going to switch surfaces like that?’ But surfaces don’t really affect me. Indoor hard is my strength.”

Parks had a chance to show the tennis world all of her strengths this week. They begin with her serve, which has a full, Sampras-esque motion, and which should be a bailout weapon for her. She also isn’t afraid to hit her second serve at the same pace as her first. Parks backs that shot up with a forehand that she can hit inside out for winners; a two-handed backhand; and no fear of coming to the net, where her overhead already looks like one of the most formidable on tour. Where Gauff wins with speed, consistency and defense, Parks wins with a relentless, modern-day power-baseline attack.

With aggression come errors, typically, and they came for Parks this week. She threw in her share of double faults and backhands that landed in the net. But what was more notable was how Parks responded to those mistakes. She excelled at saving break points, winning games from 0-30 down, staying in sets and tiebreakers after trailing, and not letting small deficits in the scoreline turn into big ones.

“We were writing Alycia Parks off when she was down a set and 2-0,” one of the European commentators calling her match on Friday said. “Not for the first time she likes proving people wrong.”

Parks is currently ranked No. 144, but she should give the U.S. yet another entrant into the Top 100 soon. Her confidence, her powerful, game and her stubborn competitiveness also prove that the Serena Williams effect will continue to play out long after Serena herself has left the stage.