In her best result ever, India No. 2 Karman Kaur Thandi pulled off an upset 4-6 6-4 6-3 win over No. 8 seed Chloe Paquet of France in the first round of Chennai Open WTA 250 tennis tournament in Chennai on Monday. (More Tennis News)

She held her nerve in the decider against the experienced French player to record a memorable win in front of a cheering crowd in the city's first-ever WTA tournament.

"This is definitely the biggest win of my career coming as it did in a 250 event," Thandi said after showing the eighth-seed the exit door.

"Even after losing the first set, I had the belief that I could turn things around the crowd support helped me a lot my opponent played extremely well," she added.

After the duo was locked in an even battle in the first few games, the Indian broke through in the seventh to nose ahead. The Indian took full advantage as Paquet appeared to lose steam in the decider. It was her first singles WTA main draw win.

The 24-year-old Thandi bounced back after losing the first set to take the second, holding serve in the 10th game despite a minor blip. She served strongly and was not afraid to go for the big shots which paid dividends against world No. 109.

She led 5-3 before allowing the Frenchwoman to reduce the margin. The lanky Thandi then held serve in the 10th game to push the match into a third set.

The Indian, ranked 359 in the world, let Paquet off the hook in the first set despite holding the advantage. She fought valiantly even in the 10th game before dropping serve to lose the first set.

"My forehand is my strength and I wanted to make the most of it," Thandi said after producing several winners.

Canada's Eugenie Bouchard, on a comeback trail from injury, began her campaign in the tournament with a 7-5 6-2 win over Joanne Zuger of Switzerland. She was joined in the second round by compatriot and seventh-seed Rebecca Marino.

The 28-year-old Bouchard roared to a 4-1 lead after losing her serve in the opening game of the match before letting her opponent back into the set. It was a set which saw the two players come up with some good shots and also numerous unforced errors.

She allowed Zuger to hit back after taking a commanding lead, committing unforced errors.

"I lost focus after taking the lead," she said after the match, adding that it was good to regain focus and win.

The Swiss player, ranked 167, bounced back after falling behind early, coming up with some impressive shots on her part. However, mistakes at crucial junctures pegged her back. The former Wimbledon finalist managed to snatch the tie-break to go a set up. She had earlier saved a set point at 5-6 with a superb backhand.

In the second set, Bouchard raised her game and won it quite easily to secure her first WTA main draw victory since March 2021.

The Canadian, who has slipped from the highs of 2014 when she won her maiden WTA title and also made the Wimbledon final, is aiming to claw her way back into the elite.

"I never thought of giving up. It (tennis) is a passion. I missed playing...I had not undergone for a surgery for 27 years but had to do so when I was 28," Bouchard said when asked if she had entertained thoughts of walking away from the sport.

Bouchard's compatriot Rebecca Marino sealed a spot in the second round when she beat Anna Blinkova 7-5, 6-2, rallying from 3-5 down in the first set. In other matches, Katarzyna Kawa of Poland eliminated Australian Astra Sharma 6-4, 6-3 and Nao Hibino of Japan thrashed Jana Fett 6-0, 6-4 in a battle of qualifiers to advance to the round of 16.

Results - Singles (1st round): Karman Kaur Thandi beat Chloe Paquet (France) 4-6.6-4.6-3, Eugenie Bouchard (Canada) beat Joanne Zuger (Switzerland) 7-6, 6-2, Katarzyna Kawa (Poland) beat Astra Sharma (Australia) 6-4, 6-3; Nao Hibino (Japan) beat Jana Fett (Croatia) 6-0, 6-4; Rebecca Marino (Canada-X7) beat Anna Blinkova (Russia) 7-5, 6-2.