Venus overcomes lethargic set to get past Petkovic in Indian Wells

INDIAN WELLS, Calif.—They say the best champions know how to win on their off days. One of the best, Venus Williams, survived a rough day in the office on Thursday, overcoming a shutout set to beat Andrea Petkovic in her Indian Wells opener, 6-4, 0-6, 6-3.

In Williams' defense, Petkovic is an esteemed opponent, one far better than her ranking of No. 68. Their head-to-head record going into the first-round match was 2-2, and Petkovic has notched wins over the likes of Julia Goerges, Belinda Bencic and Sloane Stephens over the past year.

Still, Williams was in charge of the match before falling apart without an explanation. She asked for a brief meeting during a changeover with the medical team, but accepted no treatment.

"I don’t know, honestly. I'm still trying to figure it out," Williams said about the second set. "Every day is not your best day out here, but it doesn’t mean the heart and the desire isn’t there."

When the seven-time Grand Slam champion is locked in, her powerful game remains practically unstoppable. Venus doesn't always need her best to win, but parts of Thursday's match were lethargic at best. The 38-year-old was slow to move around the court and get off the ground on her serve, and even slower while walking between points.

Williams was diagnosed with the immune system disorder Sjogren's Syndrome in 2011, but she's experienced enough to not take the court if she's not feeling well. Still, due to illness, she didn't perform post-match press duties.

"I’ve always done a smart schedule, maybe not as much training as other players. Maybe that’s why I've been here," Williams told Tennis Channel earlier this week. "I’d like to win some more."

Williams regained her form to steamroll ahead 5-1 in the final set, where Petkovic showed her signature fighting spirit to get a few more games. It's a disappointing outcome for the German, as she had a great opportunity to advance. Instead, it'll be a second-round showdown between Williams and Petra Kvitova.

Though it's unclear what, if anything, was ailing Williams, one thing is for sure: she will need to step it up a few levels if she wants a chance to upset the world No. 3.