-- LONDON -- Novak Djokovic may have found a little comfort had he glanced over to the celebrity box after losing the first set of his Tour Finals opener.
Among the guests to see his 6-7 (10), 6-0, 6-2 win against Dominic Thiem at the O2 Arena Sunday afternoon was Jose Mourinho. The Manchester United manager had departed before the evening session, when?Milos Raonic scored his first Tour Finals win, beating Gael Monfils 6-3, 6-4.
Mourinho likes his tennis and is usually spotted cheering on Andy Murray at Queen's Club, just a few minutes down the road from Mourinho's London home. He even gave the Scot some advice on dealing with pressure at the grass-court event two summers ago, following his Premier League title win with Chelsea.
But Mourinho's stock has fallen since. Sacked by Chelsea and struggling with United, the Portuguese has plenty in common with Djokovic. The Serb's ability has also been questioned, despite his dominance in recent years, after losing the world No. 1 spot to Murray following 122 consecutive weeks at the top.
Djokovic looked determined to reassert his supremacy here, though. This is his patch, after all. He is seeking a fifth consecutive title in London, and a sixth overall which would tie him with Roger Federer for the record.
More importantly, it would signal an immediate return to the top of the rankings, and guarantee him to be year-end No. 1 for the fifth time in just six years.
There are multiple permutations by which Djokovic can immediately get his old ranking back, but, like Murray, the simplest answer is that it is in his own hands. If he wins two group stage matches and takes the title, he will be the year-end No. 1.
Before the start of play, Djokovic was a combined 23-0 against his group opponents, and 3-0 against Thiem including their Roland Garros semifinal, whom he had yet to lose a set to.
Tour Finals debutant Thiem, the ambitious 23-year-old who has won titles on every surface, is touted as the next star of the men's game, and duly stood and traded with Djokovic in the first set.
"Dominic started very well, he put in a great effort and I thought we played a very high level from the very first point," Djokovic said in his on-court interview.
The crowd was brought to life when Thiem brought up two set points in the tiebreaker at 6-4. But he handed Djokovic the ultimate "get out of jail free" card by double-faulting on both. Oh, what pressure does to a player.
Djokovic would manage to save another three set points before Thiem finally took his sixth chance, closing out the first set in 67 minutes -- but only after Djokovic had failed to take one of his own.
It was unusual that Djokovic did not even attempt to intercept the forehand winner that Thiem blasted down the middle of the court. The all-conquering Djokovic of six months ago -- the best returner the game has ever seen -- would surely have been scampering after it.
Perhaps he knew it. The Serb struck a ball out of frustration, and it narrowly missed Boris Becker in his players' box.
"It was definitely not easy. He [Thiem] was going for his shots," Djokovic said. "The tiebreak was deservedly won by him. He was the better player in the tougher moments."
Almost as if he was personally affronted by surrendering his first ever set to Thiem -- and the roar that greeted it from a crowd eager to see a competitive match -- Djokovic then bageled the Austrian in just 23 minutes to level the match at one set all.
"After that [opening set] I managed to regroup and play very well," Djokovic continued. "I definitely didn't want to let him start off well in the second set. I knew the first couple of games were crucial. I managed to get a break in that opening game. After that I just felt very comfortable on the court. I put a lot of returns back and made him play an extra shot."
Thiem simply crumbled under scoreboard pressure, seeing his name in lights leading the 12-time Grand Slam winner. He won just 44 percent of points on his first serve compared to 76 in the first set.
Djokovic broke again for 2-1 in the decider and was done with it, losing just one more game to wrap up the win in two hours, two minutes.
"It was a good match with a great first set," Thiem said on court. "After the first set I lost a little bit of energy which is required to play against Novak."