For a former No. 1 player with seven Grand Slam titles to her credit, stepping on to a tennis court with no idea of what might happen must be strange indeed.

But that’s where Venus Williams finds herself as she battles back from a stamina-sapping auto-immune disease that kept her off the WTA Tour for six months.

“I always feel like I’m stepping into the unknown,” Williams said Wednesday night after a 7-5, 6-0 victory over No. 7 seed Jelena Jankovic on Stadium Court at the Family Circle Cup on Daniel Island.

Unseeded here and ranked No. 87 in the world, Venus is wasting little time in her comeback from Sjogren’s syndrome, a disease that can result in dry eyes and mouth and painful joints. She won the Family Circle Cup in 2004, and is on track to play her sister Serena in the semifinals this year.

Venus won four matches to make the quarterfinals on hardcourts in Miami last month, her first tournament since last year’s U.S. Open. And she is 2-0 on clay here in Charleston, where she says she feels like “a hometown girl.”

“Just walking around, the support in the city is amazing,” she said. “I feel like a hometown girl, like I was from here. That’s what it feels like.”

Jankovic, herself a 2007 Family Circle Cup champ, had a distinctly different feeling. “I was in the past one of the best movers on clay, and today I was falling all over the place,” said Jankovic, who beat Venus by 6-0, 6-1 when last they played, on clay in Rome in 2010. “I felt like Bambi on ice.”

The first set was tight, with many high-level exchanges between the two. But when Jankovic double-faulted on set point to hand Williams the first set, her confidence deflated quickly.

“It was unfortunate for me that I had a bad day serving,” Jankovic said. “I gotta work on that shot. I gotta work on a lot of things.”

Williams cranked up her forehand, painting the corners, and even bent low for a sweet drop shot. Jankovic had a hard time lobbing over the 6-1 Williams, as well.

“My whole mentality is so different now,” Williams said. “Before, I knew I could win matches, and now I just don’t even know what’s going to happen when I walk on the court.”

But she’s starting to get an idea.