The diminutive Panova, the world No 66, started well as she forced Seles to make 24 unforced errors in the first set before the No 2 seed found her range in a 2hr 6min match.
"I just started hitting five days ago so I'm not very confident with my shots," Seles said, referring to her return to action after problems with a stress fracture in her right foot and a left forearm injury. "I'm testing it [the foot] this week so I'll see how it goes," she said. "I really wanted to play here with the US Open coming up."
Asked if she would miss her great rival, Steffi Graf, who retired last week, Seles replied, "I'd probably have missed her five years ago, but things have changed so much and there's so many other players today."
Seles will meet the Russian Elena Likhovtseva in the third round.
The top seed, Martina Hingis of Switzerland, won her opening match with ease, beating the American Corina Morariu 6-0, 6-3. Hingis will play the 16th-seeded American Chanda Rubin in her third-round match. Rubin beat France's Nathalie Dechy 6-2, 4-6, 6-4.
Hingis was pleased with her showing against the 37th-ranked Morariu. "I just pressured her right away and she kind of didn't get into the rhythm," Hingis said.
In her post-match press conference, a relaxed Hingis discussed a wide variety of subjects. "I definitely have to watch my mouth more sometimes," she said about the controversy that has dogged her this year. "But it's all part of the learning process. Hopefully, I'm not too old or too young to learn from things."
Asked if she had a special talent, Hingis said: "I don't think I'm such a talent. It didn't just come down to me from heaven. Pete Sampras is a talent and I once asked him if he knows why he plays so well. He said he just goes out on court and it's just a feel he has from playing lots of tennis, hitting lots of balls."
The third seed, Mary Pierce, said she was happy to win but still felt her form was not what she would like after a 7-6, 6-3 victory over the Romanian Ruxandra Dragomir.
Three seeds were eliminated in the opening round with the Wimbledon semi- finalist Mirjana Lucic, of Croatia, surprising the Swiss No 2 Patty Schnyder 6-3, 6-7, 6-3. Anke Huber, of Germany, overwhelmed the Romanian Irina Spirlea 6-2, 6-1 and Anne-Gaelle Sidot, of France, beat the American Amy Frazier 6-3, 3-6, 7-5.Reuse content