Djokovic triumphed 6-4, 4-6, 2-6, 6-3, 6-4 in one minute short of four hours in Melbourne.
The Serb had to dig deep to beat the Austrian, who had triumphed in four of their previous five meetings. Thiem rallied after falling a set behind to get in front of the No. 2 seed, who struggled in the second and third sets.
Djokovic clashed with the umpire over a time violation in the second set and sought a medical timeout for dizziness and dehydration in the third, but he recovered to level proceedings in the fourth and put on a show in the final set to secure victory:
The 32-year-old extended his Australian Open record ahead of Roger Federer, who has won six titles at Melbourne Park, and defended his 2019 title in the process:
He has been imperious in Grand Slam finals of late:
BBC Sport tennis correspondent Russell Fuller shared some of the numbers behind Djokovic's illustrious career and suggested fatigue may have been a factor in Thiem's failure to see out the match:
Prior to the final, the No. 5 seed had played three four-set matches and one five-setter, while Djokovic had only been taken to four sets twice. Thiem had also played seven tiebreakers to the Djoker's three.
Ben Rothenberg of the New York Times would have welcomed a new face winning a Grand Slam:
According to Christopher Clarey of the same outlet, there have been just seven different male Grand Slam winners since the start of 2006, compared with 25 different champions in the women's draw.
Since Djokovic won his first Australian Open title in 2008—his first Grand Slam—he's only failed to win a major in 2009, 2010 and 2017. When all titles are taken into account, his consistency has been even more impressive:
Djokovic now has 17 Grand Slam titles overall. He's just two behind Rafael Nadal's 19 and three behind Federer's 20.
Federer turns 39 this year, and Djokovic is a year younger than Nadal, who has had significantly more injury issues to deal with over the course of his career, so he has an excellent chance of surpassing both by the time they've all retired.
As for Thiem, the 26-year-old has now reached a Grand Slam final for three years running. He's beaten Djokovic and Nadal four times apiece and holds a 5-2 head-to-head record against Federer, so if anyone is poised to break the trio's stranglehold on the Grand Slams, it's him.