It looks like defeating Novak Djokovic at the Barclays ATP World Tour Finals is going to take something approaching a flawless effort. After Sunday's crushing 6-1, 6-1 win against Kei Nishikori to open the year-end event, Djokovic doesn't seem to be contemplating any charitable donations.
He beat Nishikori in 65 minutes, taking 60 of 92 points.
It was the 23rd consecutive win for the No. 1-ranked Serb -- and his 15th straight at this tournament.
"I think I was at my best," Djokovic said afterward. "Undoubtedly it's been an incredible performance that I was hoping I can have coming into the match, coming into this tournament where I've had a great record in last couple of years.
"Reflecting back on those memories of course gives me more confidence, more comfort coming into every single match."
In the other Group Stan Smith singles match, Roger Federer handled Tomas Berdych 6-4, 6-2 to wrap up the night session. Federer, a six-time year-end champion, needed only 70 minutes to dispatch the Czech Republic player.
Before Djokovic took on Nishikori to begin play at the O2 Arena, there was a moment of silence for the victims of terrorism in nearby Paris.
"Today I've had for an opponent one of the quickest tennis players, somebody that possesses a lot of talent and loves to play aggressively," Djokovic said. "But I didn't allow him to dictate the play. I mixed up the pace. I was feeling very comfortable on the court, feeling like I could get most of the balls back."
Biggest winner: Federer. At 34, the Swiss champion is the oldest player to qualify for the ATP Finals since Andre Agassi (35) a decade ago. The No. 3 seed is the only player to hold two wins this season against Djokovic. And Tuesday, Federer will get a chance for a third when we takes on the Serb in a scintillating round-robin matchup in London.
Biggest loser(s): Bob and Mike Bryan. The No. 1 double seeds were stunned by the No. 8-seeded team of Rohan Bopanna and Florin Mergea 6-4, 6-3. The 37-year-old California twins are the most-decorated doubles team in men's tennis history and are the defending champions.
Quote of the day: Nishikori: "Today I couldn't do anything. Even at the start of the match, it was half my fault, because I didn't make any first serves. He was attacking my second serves, too. I was playing defense all the time. But he played great defense so many times where I usually hit the winner or I get the point. He also made me run side to side. I didn't feel any chance today."
Up next: Tuesday's featured match from the Group Ilie Nastase pits nine-time French Open champion Rafael Nadal against 2015 French finalist Stan Wawrinka. Andy Murray takes on David Ferrer in the other singles meeting.