Progress has been slow but steady for Petkovic since returning from four months out with a serious ankle injury, and she was made to work hard by World No.290 Shapatava.
Petkovic, who after starting the year inside the Top 10 is now down at No.143, struggled to find her timing and with her opponent's aggressive approach in the early stages, falling 5-2 behind in the opening set. Despite breaking back, the German was then forced to fend off two set points before nicking the set on the tie-break.
The second set was just as closely fought; Shapatava securing an early break only for Petkovic to peg her back once more and eventually close the match out, 76(4) 75.
"I hadn't practiced on the main court yet, so I was not used to it, and it is faster than the practice courts," Petkovic said. "At the start of the match I struggled to adjust and she played really well and really aggressively, putting me under a lot of pressure.
"Finally, I found the rhythm and did enough to get through. I am very happy to win and feel fit and healthy on the court."
No.1 seed Bratchikova did not have things all her own way against Nudnida Luangnam, who kept her on court for nearly two hours before going down, 64 63. Doi, who broke into the Top 100 for the first time on Monday, had a far easier time of things, racing past Indian wildcard Prerna Bhambri, 60 62.
"It was a tough match and I am happy to get the win in the end," Bratchikova said. "I really like it here in India. I've been here quite a few times before, the weather suits my game and it is easy for me to adjust."