Serena Williams beat Italian teenager Lisa Pigato in Parma as part of the American's bid to build up clay-court sharpness before the French Open.
The 39-year-old was given a late wildcard into the event after losing her first competitive match since mid-February at last week's Italian Open.
The 23-time Grand Slam champion needed an hour and eight minutes to win 6-3 6-2 against 17-year-old Pigato.
"Lisa played really well," Williams said. "Her future is super-bright."
Pigato was born a fortnight before Williams won her sixth Grand Slam title at Wimbledon in 2003.
The qualifier, ranked 572nd, broke Williams' serve in the first game of the match, before the world number eight quickly found rhythm and asserted her authority.
"She played really good and I needed to adjust to get back," top seed Williams said after her first victory on the red dirt in 2021.
"She handled the moment well, so I look forward to cheering for her in the future."
Williams will be going for a record-equalling 24th Grand Slam title, matching the number won by Australian Margaret Court, when the French Open starts on 30 May.
Meanwhile, British men's number two Cameron Norrie set up a second-round meeting in Lyon with US Open champion Dominic Thiem.
Norrie, who been impressive on both hard courts and clay this season, won 7-5 6-3 against France's Corentin Moutet in his opening match.