Novak Djokovic was yet again a class apart as he claimed a record 15th straight ATP World Tour Finals victory in the first game of the tournament against Kei Nishikori.
The world number one has won the season-ending extravaganza three years in a row and it is difficult to envisage him failing to triumph for a fifth time in total in London.
Djokovic stretched his winning run to 23 matches by outclassing Nishikori, coasting to a 6-1 6-1 victory in the Group Stan Smith opener at the O2 Arena in only 65 minutes - and breaking the record for the longest winning run in the tournament.
The top seed wasted no time in stamping his authority on the match, racing into a 3-0 lead in ruthless fashion as Nishikori failed to come up with any answers to his power and precision.
Djokovic has won 10 titles - including three grand slams - in what has been the year of his career and showed why he has become the dominant force in men's tennis by conjuring up an array of classy winners in a commanding display.
Nishikori attempted to take Djokovic on from the baseline, but that tactic never looked like paying off as the Serb's steadfast defence was combined with the usual ruthless attacking shots which have brought him so much success.
Djokovic, who also faces Roger Federer and Tomas Berdych at the round-robin stage, finished off the job with a sumptuous backhand volley into the corner to put eighth seed Nishikori out of his misery.
The Serb was presented with the trophy for finishing the year as the world number one and it would be a surprise if he is not celebrating winning another piece of silverware come the end of the tournament.
Djokovic  bt Nishikori  6-1 6-1
Djokovic - 5
Nishikori - 3
BREAK POINTS WON
Djokovic - 5/9
Nishikori - 0/0
FIRST SERVE PERCENTAGE
Djokovic - 72
Nishikori - 53
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Djokovic - 82/63
Nishikori - 42/44
Djokovic - 60
Nishikori - 32