Novak Djokovic has made an impressive start to his campaign for a sixth ATP Finals title by dismissing John Isner in their opening group match.
A day after a ceremony to mark ending the season as world No.1, Djokovic underlined his status in a near-faultless 6-4 6-3 victory in one hour and 13 minutes against the tournament debutant.
Djokovic dropped just six points on his own serve and made only six unforced errors.
The Wimbledon and US Open champion nullified Isner’s usually destructive serve and could have easily had more than the sole break he managed in the opening set.
“It’s great to be back in the O2, it’s been a lucky place for me over the years,” Djokovic, a five-time winner of the elite eight-man tournament, said.
“I missed this tournament last year because of injury. I kind of enjoyed the time off but I missed this arena and I’m glad to be back.”
Isner, who at 33 became the season-ending tournament’s oldest newcomer since 1972, applied himself admirably but the big-serving American was broken twice more in the second set.
“The match was great,” Djokovic said.
“I managed to get three breaks of John’s serve which is sometimes mission impossible, but I managed to be at the right place at the right time and I held my serve very well and played solid.”
Earlier on Monday, Alexander Zverev came from a break down in both sets to defeat Marin Cilic 7-6 (7-5) 7-6 (7-1).
Zverev nailed a trademark backhand winner down the line to earn five more match points and converted the first with a powerful first serve that Cilic could only fend into net.
“The win, that’s the most important thing,” Zverev, who failed to advance from the round-robin stage on his debut last year, said.
Facing each other in their opening match for a second straight year, Zverev produced the slightly steadier tennis in an error-strewn two hour and six minutes contest to extend his record against Cilic to 2-0 at The O2 arena and 6-1 overall.
“I was just trying to get myself going, trying to get the energy up. It worked out,” Zverev said.
Cilic, who made 46 unforced errors, dropped to 1-9 across his four appearances at the end-of-season tournament.