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.