The Indian mixed doubles pair of V Diju and Jwala Gutta overcame early sluggishness to beat Singapore's Chayut Triyachart and Lei Yao and enter the quarter-finals in the World Badminton Championships in Paris on Thursday.
Diju and Jwala, quarter-finalists at the last World Championships in Hyderabad, won 14-21, 21-18, 21-14.
The Indians now face 12th seeds Sung Hyun Ko and Jung Eun Ha of South Korea for a place in the semi-finals.
The Korean pair shocked fifth seeds Joachim Fischer Nielsen and Christinna Pedersen of Denmark.
"I don't think we were at the top of our game," said Diju. "We made too many mistakes and it's only later that we managed to piece our game together."
The Singapore pair was no pushover, something the ninth seeded Indians realised fast enough. A lead of 14-13 for Singapore soon became 20-14 before another error at the net from the Indians gave the game away.
Down 0-1, Gutta and Diju knew their work was cut out. The placements got slightly better and Gutta started dominating the net as the lead remained with the Indians at 15-12.
A rash of errors gave the Singapore pair the chance to equalise at 15-15 as the game became tense. India led 17-16 before bad judgment by Diju ensured the Singapore pair equalised again at 17-17.
"I think that was the turning point," said Gutta. "We knew if we played to a plan, kept the shuttle in mid court, we could clinch the second game."
At 20-18, Gutta served for the second game. The serve was perfect as the shuttle dipped in, forcing Yao Lei to hit into the net.
Confident after equalising, Gutta and Diju played the mid court well and kept the Singaporean pair guessing. High tosses, delicate net play and finally some smashes from the Indians emerged to keep Chayut and Yao at bay.
After the scores were equalised at 10-10, suggesting a close decider, the Indians reeled off points to lead 17-11.
Gutta's net play was eye-catching as she placed it craftily to keep reeling in the points. At 20-14, match point, India forced yet another error from the Chayut-Yao to clinch the match and a place in the quarter-finals.
"I think a day's gap made us complacent," said Gutta. "But we will be ready for the Korean pair. We would do our best to clinch a semi-final spot at the World Championships."
The Indians had only recently beaten the Korean pair in the Singapore Open Super Series 23-21, 21-16.