Rohan Bopanna and Florin Mergea downed No. 1 seeds Bob and Mike Bryan 6-4, 6-3 in their opening match at the Barclays ATP World Tour Finals on Sunday. The eighth-ranked team needed exactly one hour to secure the straight-set victory.

Despite playing in serve-friendly indoor conditions at the O2 Arena in London, the outcome of the match was decided the winning team’s return quality. The Bryans drew first blood by breaking Bopanna/Mergea in the second game on the match, starting a run which saw the returning team claim five of six service games. The latters snapped the streak by saving three break points and holding for a 5-3 lead, before serving out the set two games later.

Bopanna/Mergea kept up the pressure at the start of the second set, winning a deciding point on the Bryans’ serve to move ahead for good. In total, they were five-for-11 on break points during the match while the Bryans were two-for-seven.

With a 1-0 record, Bopanna/Mergea join Jamie Murray and John Peers at the top of the Group Ashe/Smith tables.