Roger Federer came from a set behind to beat Fernando Verdasco 4-6, 7-5, 6-1 in his opening round-robin match at the London-based ATP Tour Finals.
The audience inside the O2 Arena might have sensed an upset was on the cards when top seed Federer's serve was broken to love in the first game of the match.
World number eight Verdasco was soon warned by the umpire about the amount of time he was taking in between points but the ticking off didn't spoil his concentration as he proceeded to take a set off Federer - a feat he had failed to achieve in their previous three meetings.
Federer, wearing a black shirt, was in no mood to let Verdasco make further history, putting the Spaniard's serve under pressure as he looked to level the match.
Verdasco, using his big serve and forehand, lasted out until game 12, a game in which he misjudged a Federer lob, allowing the Swiss star to force a deciding set.
With Federer now in the groove and breaking at the first opportunity, the match looked over.
And so it proved, a love service game wrapping up the set 6-1 after the final part of the contest became as one-sided as the Spurs v Wigan match which had ended 9-1 earlier in the day.
The 15-time Grand Slam winner is now top of Group A with Andy Murray, who defeated Juan Martin del Potro in three sets in the afternoon session.
Murray and Federer are scheduled to play against each other for the first time on British soil on Tuesday, with the winner virtually assured of a place in the semi-finals.