Roger Federer loses again to Novak Djokovic at ATP World Tour Finals

This is the first time Roger Federer has lost his opening round match of the ATP World Tour Finals since the tournament moved to London. (Ben Stansall/Getty Images)

LONDON -- Roger Federer said he would try to remain positive after losing his second three-set match to Novak Djokovic in three days, a 6-4, 6-7 (2), 6-2 defeat in group play at the ATP World Tour Finals on Tuesday. Federer looked emotionally deflated after the loss, in which he played a great second-set tiebreaker to force a third set before Djokovic's impenetrable defense left him without answers.

Asked if he could take positives away from his last two matches against Djokovic, who also won their meeting in the Paris Masters semifinals Saturday, Federer responded sarcastically. "Yeah, sure," he said. "Let's see it that way. Great, we're positive. It was great to win two sets off Novak and losing four. Losing a match, it's really exciting."

That said, the 32-year-old Federer was pleased with how well he was able to recover physically after back-to-back tournaments in which he played nine matches in 12 days, but he was disappointed with his uneven play. With the crowd firmly behind him after he leveled the match at a set apiece, Federer was broken at love in the first game of the third set and couldn't recover.

"Obviously, It's been a tough season overall," he said. "So I guess I'm just rattled at times with my level of play consistently. So I regret not having taken my chances better maybe, maybe played it a bit tougher, a little bit more solid overall."

Federer has won the World Tour Finals a record six times, but this is the first time he's lost his opening match since the tournament moved to London in 2009.

"I think at this point it's very mental, just making sure I don't get too negative on myself because of the loss today," he said. "It was against Novak, after all. It's not against some journeyman."