India's Leander Paes and Mahesh Bhupathi faced their first defeat after their reunion going down to Mark Knowles of Bahamas and Daniel Nestor of Canada in the quarter-finals of the ATP Tennis Masters in Cincinnati on Friday.

The eighth seeded Indian pair could not show the same magic which won them the Masters title in Toronto, Canada last week and went down in straight sets, 3-6, 4-6.

Earlier, Paes and Bhupathi had defeated Leos Friedel and Frantisec Cermak of the Czech Republic 6-7, 7-6, 7-5 to enter the quarterfinals.

Paes and Bhupathi are teaming after more than two years to prepare for the Olympics, beginning on August 13. The former world No.1 doubles pair had taken the tennis world by storm in 1997, winning their first major title together on the ATP tour at the 1997 Gold Flake Open.

They won 12 titles thereafter leading up to a sensational 1999, which saw them become the first pair since 1952 to reach all four Grand Slam finals and win the Wimbledon and French Open.