By Piers Newbery
BBC Sport at the O2 Arena
The Bryans lost to Mirnyi and Ram in the round robin stage
Mike and Bob Bryan took the season-ending ATP World Tour Finals title for the third time and earned the year-end number one ranking with victory over Max Mirnyi and Andy Ram in London.
The American twins had lost to the seventh seeds in the round-robin stage but edged a tight final 7-6 (7-5) 6-3.
After an opening set in which serve dominated, the breakthrough came on the first set point when a fizzing backhand split the Belarussian-Israeli pairing and prompted the trademark Bryan brothers chest-bump.
A single break in game eight of the second set was enough for the brothers to serve it out before the pair fell to their knees, clearly thrilled to have regained the title and the top ranking.
The Bryans will now overtake last year's champions Daniel Nestor and Nenad Zimonjic to end 2009 as the number one pairing in the world.
They also won the year-end title - then called the Tennis Masters Cup - in Houston in 2003 and 2004.
To showcase doubles in this stadium was huge... Over the last few years, I think doubles is gaining a little bit of notoriety
"It means so much," said Bob Bryan of regaining top spot.
"It's pretty much what we play for, that's the goal - play well in the Slams, but the ultimate goal is to finish number one.
"We felt like it was stolen from us last year, now we kind of crept up on those guys and stole it from them this year. We feel like it's a little bit of a payback."
With the doubles matches scheduled before the singles, the players enjoyed playing to nearly full houses in every session at the 17,500-capacity O2 Arena.
"To showcase doubles in this stadium was huge for doubles," said Mike Bryan.
"It was on TV, 16,000 people watching - it doesn't get any better than that for doubles.
"Over the last few years, I think doubles is gaining a little bit of notoriety. Singles players are playing, the scoring format is exciting, they're playing more matches on stadium court.
"To see this atmosphere for a doubles match is unbelievable."