Don’t miss your first serve against Novak Djokovic.

The Serbian started slow, but stormed home to defeat Dominic Thiem 6-7(10), 6-0, 6-2 in his opening-round match at the Barclays ATP World Tour Finals on Sunday afternoon. Djokovic was not in top gear, and relied heavily on winning the second serve battle to find separation from his up-and-coming opponent.

When Thiem made a first serve during the three-set match, he won 67 per cent (43/64) of the points. Problems immediately developed when he didn’t.

Thiem won 54 per cent of his second serve points in 2016 leading into the ATP Finals, making him 14th-best on the ATP World Tour in this category. But against Djokovic, that was chopped all the way down to just 34 per cent (11/32). Thiem won 41 per cent (7/17) in Set 1, 22 per cent (2/9) in Set 2, and just 33 per cent (2/6) in the deciding third set. It really didn’t matter what else was going on in the match, the bleeding was too great in this area to find a pathway to victory.

On the other side, Djokovic was the master of his own second serve, winning a mind-blowing 77 per cent (20/26), which actually ended up being higher than the 72 per cent (39/54) he won on his first serve.

Thiem’s problems continued from there. Court position became a real issue for the Austrian, as Djokovic regularly played closer to the baseline, dictating more of the baseline exchanges. Thiem’s forehand broke down the most, committing 27 unforced errors, compared to only 16 off his backhand wing.

Thiem consistently preferred to add height and spin to his forehand, which works perfectly on clay where he had a lot of success this year, but less so in London on an indoor hard court. Djokovic’s groundstrokes penetrated the court more, pushed Thiem further back behind the baseline, and wrestled control of what promised early on to be a very close encounter.

As often happens, the match loser (Thiem) actually hit more winners (28-22), but it was the escalating error count that mattered the most. Thiem was increasingly losing the baseline battle, and had no safe haven at the net either, winning only 31 per cent (5/16), while Djokovic was far more successful coming forward, winning 72 per cent (18/25) of such points.

Djokovic credited breaking serve at the start of the second set as the turning point in the match. “The first game of the second set, when I made the break, I knew that even though it’s only the first game, it was a significant lead,” he said. “We didn't have any breaks of serve in the first set.”

The early break indeed played a big part in wrestling control of the match, as Djokovic only lost 10 points in the second set, none of which were in extended rallies of five shots or longer.

Thiem will take confidence moving forward from winning the opening set, where he won the critical short exchanges of 0-4 shots by a margin of 29-23, but will need to find the stamina to do it for two or possibly three sets in the next round.

Thiem said post-match: “It was a very good and very intense first set. After that, I lost a little bit of energy, which is required against a guy like Novak to play close and good sets.”