Mahesh Bhupathi and Max Mirnyi booked a semi-final berth in the World Tour finals for the first time in their careers after beating Wesley Moodie and Dick Norman 6-4, 6-4 to grab the last available spot.
They had qualified for the season-ending finale after six years and have cleared the round-robin stage for the first time, having failed in 2003 and 2004.
They ended runners-up in Group B and will take on Group A winners Mariusz Fyrstenberg and Marcin Matkowski of Poland in the fight for the final.
In the second semi-final, defending champions and American twins Bob and Mike Bryan will meet the winners of Group B, Daniel Nestor and Nenad Zimonjic.
Bhupathi conceded the Pole pair is tough to beat but exuded confidence of maintaining their supremacy over them.
"(They) are obviously playing their best tennis of the year. They won the group, but we've beaten them every time we've played them this season. It's going to be a good game. (The atmosphere at the O2) is awesome; every day we can stay alive in this tournament it's a bonus for us. Hopefully we can keep going till the weekend is over," he said.
Bhupathi and Mirnyi drew first blood with a break of serve in the third game. Bhupathi hit a return winner off the Moodie serve, which the crossing Norman could not reach.
Untroubled on serve, the third seeds went on to seal the first set with a hold to 15 by Mirnyi in the 10th game.
Moodie's serve was broken at exactly the same stage in the second set as Bhupathi and Mirnyi quickly raced to a commanding 5-3 lead.
The Indian-Belarussian duo earned two match points in the ninth game after a superb backhand winner off a smash by Bhupathi.
They failed to convert those opportunities, but made no mistake as Mirnyi served out victory in the following game after 78 minutes.
"It is nice being in the semi-finals. Going into the match it was a must-win situation for us, so we were glad to get it done. We played pretty well, very solid. I thought we served really well and happy that we won.
"The pressure goes both ways, for them and us, but definitely when we got the early break to go up 2-1 that eased the tension. Moodie and Norman are always a very dangerous team with the way they serve, but happy that we got through," he said.
