Briton Laura Robson beat Venus Williams 6-3, 6-2 in blustery conditions at the ATP/WTA Rome Masters on Monday and now faces the second half of a one-two punch when she next plays Williams' sister and world number one, Serena.
The top-seeded American, who was watching from the stands, has targeted this week and hopes to follow up her Madrid trophy from the weekend.
The 39th-ranked Robson moved through to the second round in just under 90 minutes against Venus, the 1999 Rome winner now ranked 24th.
The five-time Wimbledon winner committed six double-faults, and dropped serve five times. Robson, 19, closed it out on her third match point.
Venus pulled out of her first match last week with back pain and had reportedly been training at half strength in Rome.
Elsewhere in women's play, Australian Samantha Stosur came third time lucky in her pre-French Open campaign, with the ninth seed finally scoring a 2013 European clay victory 6-2, 6-3 over Hsieh Su-Wei of Taiwan.
Stosur wasted no time in getting to Rome after her opening loss last week in Madrid to Carla Suarez Navarro, with 2010 Roland Garros finalist Stosur glad to get some work in on her game. She was also winless in Stuttart last month.
"I really like the surface, the clay courts here are very light and the ball gets through the air pretty quickly," said the Australian. "As long as it's not too windy it's great."
Germany's Sabine Lisicki beat American Madison Burdette 6-1, 6-2, but German sixth seed Angelique Kerber withdrew prior to her opening match with an abdominal injury and was replaced by Lourdes Dominguez Lino of Spain.
China's Peng Shuai defeated Romanian Monica Niculescu 4-6, 6-3, 6-2 while Italian Nastassja Burnett put out 2008 finalist Alize Cornet of France 6-2, 6-2.
Amongst the men, Potito Starace set up his seventh career meeting with Roger Federer with a 4-6, 6-4, 6-3 comeback win over Czech Radek Stepanek.
Starace, ranked 293 after reaching 27th on the ATP computer in 2007, needed nearly two-and-a-quarter hours to get past Stepanek, whom Federer beat last week in the second round in Madrid.
Starace had lost both of his previous matches with the 34-year-old Czech, who underwent surgery in January to relieve pressure on a nerve in his neck
Federer holds a 6-0 record over Starace, beating the home player in Rome at the Foro Italico in 2006 and earning a straight-sets victory in their last meeting indoors in Basel in 2011.
While leading seeds waited to get started in the second round after byes, the big names at the joint event filled up the practice courts at the last-chance tune-up week prior to the start of the French Open on May 26.
France's Benoit Paire earned a second-round spot at the expense of Argentine Juan Monaco 7-6 (7/4), 1-6, 6-4 while Spaniard Albert Ramos defeated Czech Jan Hajaek 7-5, 6-0.
Russian Alex Kuznetsov advanced as Belgian veteran Xavier Malisse quit their match trailing 6-2, 3-1.