London, England (CNN) -- Roger Federer enjoyed a comfortable 6-1 6-4 victory over David Ferrer to join Andy Murray at the top of Group B at the ATP World Tour Finals at London's O2 Arena on Sunday evening.
The four-time winner of the season finale had never lost to the Spaniard in 10 previous meetings and it became clear from the start that an upset was unlikely.
The 29-year-old Swiss broke the seventh seed twice to open up a 4-0 lead in the opening set, before Ferrer hit back with a break of his own.
But normal service was resumed in the sixth game, despite the Spaniard's best efforts as Federer broke his serve again and then served out the set.
The second set was less one sided, with Federer taking five games to secure a break of serve, but the result was the same.
Serving for the match at 5-4, the number two seed experienced an uncharacteristic lapse in concentration, handing his opponent three break points.
But, as so often with Federer, he immediately regained his composure to save all three and then promptly served an ace to wrap up the match.
Earlier in the day, Andy Murray made the perfect start to his campaign defeating Robin Soderling in straight sets 6-2 6-4.
The 23-year-old Scot swept the Swede aside in just one hour and 20 minutes.
Murray, who hadn't beaten Soderling since 2006, found the new world number four in curiously sedate mood.
Soderling, who won his first Masters title in Paris last weekend, never managed to get going and was comprehensively outplayed.
In front of a partisan crowd at the 17,500 capacity arena Murray quickly found his rhythm breaking Soderling in the third and seventh games to establish a 5-2 lead.
He made no mistake on his next service game and duly served out the first set in 29 minutes.
The second set was closer and Soderling, a semi-finalist here last year, earned himself an opportunity to break in the sixth game, but Murray held his nerve serving an ace.
To compound his frustration, Soderling then concluded a messy service game with a double fault, handing Murray a crucial advantage which he never looked like surrendering.
The world number five duly served out the match to record his 45th victory of the season.
In the opening Group A doubles matches, defending champions Bob and Mike Bryan opened with a 6-3 7-5 win over Jurgen Melzer and Philipp Petzschner.
Sixth seeds Mariusz Fyrstenberg and Marcin Matkowski overcame third seeds Lukas Dlouhy and Leander Paes 6-3 7-6.