- Images from Tuesday's matches
Sania, who finished runner-up at last week's Bank of Western Classic in Stanford, will now take on Greek Eleni Daniilidou at the event which would be eliminated from next year's WTA calendar.
In a two-hour-three-minute contest where the momentum kept swinging back and forth, both Sania and Peer pounded heavy ground strokes from the baseline to make it an exciting match for the sizeable crowd at the Stadium Court.
Sania used her strong forehand to set up winning points and kept Peer under pressure with her service returns. There were a combined 15 service breaks in the match.
After splitting the first two sets, Sania opened the final set by holding serve and breaking Peer to take a 4-1 lead.
Later, leading 5-2 Sania got to match point when she slammed a high forehand volley for a winner. On the next point, the Indian landed a cross court forehand which Peer could only return into the net.
After the win, the world number 31 said it was the toughest first-round match that she could get, as she had to play against a good friend.
"Neither of us was happy to see that we had drawn the other because we are friends and it's hard to play a friend. It was the toughest first round I could have had. I played well under the circumstances," she said.
"I wanted to spend the least amount of time possible on the court. But I won the match in the end, and that's the most important thing," she added.
Sania and Peer won the doubles title at Stanford last week and have paired up for this tournament as well.
The seventh seeded duo will open its campaign against German Angelika Bachmann and Czech Hana Sromova.
Other results:
5-Marion Bartoli (France) beat Aiko Nakamura (Japan) 7-6(4), 6-1
First round:
* Alla Kudryavtseva (Russia) beat Julia Vakulenko (Ukraine) 6-1, 6-3
Katarina Srebotnik (Slovenia) beat Nicole Pratt (Australia) 6-1, 6-4
Virginie Razzano (France) beat Yaroslava Shvedova (Russia) 7-6(2), 6-4
Sania Mirza (India) beat 12-Shahar Peer (Israel) 6-3, 4-6, 6-2
Ai Sugiyama (Japan) beat Akgul Amanmuradova (Uzbekistan) 6-3, 6-2
15-Sybille Bammer (Austria) beat Katerina Bondarenko (Ukraine) 6-4, 7-6(5)
Victoria Azarenka (Belarus) beat Chan Yung-Jan (Taiwan) 4-6 6-3 6-0
16-Lucie Safarova (Czech Republic) beat Meilen Tu (U.S.) 6-4 6-3
Meghann Shaughnessy (U.S.) beat Olga Poutchkova (Russia) 6-3 6-1
Photograph: Getty Images
Lean, mean Sania eyes top 20
Sania loses in Stanford final
Images: Sania loses in Stanford final