World no. 1 and the five-time ATP Finals champion Novak Djokovic made a winning start in London, beating a debutant Diego Schwartzman 6-3, 6-2 in an hour and 18 minutes. Chasing the first ATP Finals crown in five years, Novak had the upper hand almost all the time, securing the 37th victory at this event and leaving his former coach Boris Becker on 36.
The Serb played well behind the serve and from the baseline, controlling the rallies' pace and overpowering the opponent with deep and precise groundstrokes. Djokovic lost serve once in the early stages and grabbed four in the rest of the clash to control the scoreboard.
Novak held at love in the first game after two aces at 30-0 before the Argentine got his name on the scoreboard in game two when the Serb landed a backhand long. Unlike in the opening game, Djokovic had to work harder at 1-1, netting a forehand and offering two break chances to the Argentine.
Diego forced an error from Novak at the net to confirm the second and open a 3-1 lead, making a strong start against the five-time champion. Staying calm, Novak won a battle of forehands in game four to pull the break back and level the score at 2-2 before holding at love to regain the advantage.
The ATP Finals debutant landed two winners at 30-30 in the sixth game to remain on the positive side, hoping for more chances on the return. Novak landed a forehand down the line winner in game seven and fired another direct point from his right wing to grab the second break and open a 5-3 gap.
Novak Djokovic became the third player with 37 ATP Finals victories.
The Serb wrapped up the opener with a service winner in game nine after 40 minutes, looking good so far and hoping for more of the same in set number two.
The five-time winner had the upper hand with 12 winners and nine unforced errors, beating the rival in the shortest, mid-range and most extended exchanges to take a massive step towards the finish line. Schwartzman squandered a game chance in that eighth game when he got broken, repeating that in the first game of the second set and suffering a break following Djokovic's smash winner.
Novak confirmed the break with three winners in game two, looking better and better on the court. Deigo reduced the deficit to 1-2 with an ace, with Novak moving 3-1 in front when his rival netted an easy backhand. With no room for placing his strokes, Schwartzman gave serve away for the second time in game five, pushing Djokovic 4-1 ahead and closer to the finish line.
With nothing to stop him, Novak held at 15 with a service winner to move 5-1 up and force Diego to serve for staying in the match. The Argentine hit a service winner to bring the seventh game home and extend his chances before Novak held with a volley winner a few minutes later to move over the top.