Canada's Andreescu victorious in return to court at Porsche Tennis Grand Prix

Canadian tennis star Bianca Andreescu was victorious in her return to action after a long layoff.

The 21-year-old from Mississauga, Ont., overcame some nervy moments in the first set en route to a 7-6 (5), 6-3 win over Germany's Jule Niemeier on Tuesday in first-round action at the Porsche Tennis Grand Prix in Stuttgart, Germany.

Andreescu trailed 5-3 in the first set before rallying to win, then went up a break early in the second set en route to the victory.

Andreescu, ranked 121st in the world due to a months-long absence, was given a wild-card berth into the tournament. She will next face third seed Aryna Sabalenka of Belarus.

Tuesday's match was the first of the 2022 season for Andreescu, who announced in December that she was stepping away from tennis to recover physically and mentally from a "challenging" two years.

WATCH l Canada's Andreescu advances to 2nd round in Stuttgart:

Andreescu posted on Twitter that she was affected by "multiple weeks in isolation quarantining" after contracting COVID-19, and by her grandmother's stay for several weeks in a hospital's intensive care unit because of the coronavirus.

Her last match before Tuesday was a second-round loss to Anett Kontaveit at Indian Wells on Oct. 21.

"A lot of days, I did not feel like myself, especially while I was training and/or playing matches. I felt like I was carrying the world on my shoulders," Andreescu said. "I could not detach myself from everything that was going on off the court; was feeling the collective sadness and turmoil around and it took its toll on me."

Andreescu was 19 when she capped a breakthrough season by upsetting her idol, Serena Williams, in the 2019 U.S. Open final. That win came a couple of weeks after she won the Rogers Cup final in Toronto when Williams retired early in the final.

The strength of those wins propelled Andreescu to a career-best No. 4 in the WTA rankings.

American Coco Gauff was knocked out in the first round after a 6-4, 6-2 loss to Daria Kasatkina.

The 18-year-old Gauff seemed in control when she was 4-0 up in the opening set but Kasatkina recovered to win the next six games, then only dropped two more as she wrapped up the win in 1 hour and 19 minutes.

Earlier, Elena Rybakina defeated another young German qualifier, Nastasja Schunk, 7-6 (3), 7-5 and next meets the second-seeded Paula Badosa in the second round.