Andy Murray marked the beginning of the ATP World Tennis Tour Finals with a 6-3 3-6 6-2 win over U.S. Open champion Juan Martin del Potro in front of 17,500 fans in London.
The Briton withstood a ferocious comeback by Argentine Del Potro, to open his account in Group A which also contains world number one Roger Federer and Fernando Verdasco who play later today.
After thumping rock music and swirling spotlights greeted the players on court, Murray won a nervy opening game by saving a break point with an ace before striding into a 5-love lead as Del Potro's dynamite forehand failed to ignite.
However, the Argentine began to use his albatross-like wingspan to good effect as the set wore on and although Murray finally clinched the opener on his seventh set point the tide had turned in the giant South American's favour.
Del Potro broke serve twice in the second set and after levelling the match with an unstoppable forehand he looked the more likely winner.
However as quickly as it had sparked into life Del Potro's challenge withered in the decider after he dropped serve in the second game to hand the momentum back to world number four Murray.
A double fault gifted Murray two match points and he swiped away a crosscourt backhand to complete a victory that puts him on course for the semi-finals of the season-ending showpiece.
Group B action opens tomorrow when Rafael Nadal, who can still beat Federer to the year-end world number one ranking, faces Swede Robin Soderling before Novak Djokovic takes on Nikolay Davydenko.