Djokovic started the match the stronger player, although Thiem was able to gradually exert his authority on the contest, recovering well after losing the first set to level things up.
After moving ahead with some dominant play, the Austrian appeared on course for a four-set win, although Djokovic dug deep to recover, taking the match to a deciding stanza.
In it, the second seed secured an early break and went on to clinch his 17th Grand Slam title, putting him just three behind Roger Federer's record men's haul of 20.
Here is the moment Djokovic got over the line:
Thiem got off to the worst possible start with a nervy opening service game. The fifth seed quickly found himself 3-0 down, although midway through the set there were signs he was settled. He was able to break Djokovic and claw his way back to parity at 4-4, looking like a completely different player.
But at this point, the defending champion found another gear, starting the next game with this brilliant point:
After holding serve, Djokovic got his teeth into the Thiem serve. Thiem was clearly edgy at this point too, with a number of mistakes costing him the game and ultimately the set.
The Tennis Podcast commented on how ruthless Djokovic is in Melbourne when he does get ahead:
However, he was unable to maintain those levels, with Thiem taking it to him in the second set.
He broke early, only to be pegged back by a pumped-up Djokovic later on. At 4-4, it looked as though the Serb would press on again, but his game unexpectedly deserted him. A double-fault on break point handed the break back to Thiem, who went on to win the set.
After such a strong start to the match, errors were creeping in to Djokovic's play:
It got even worse at the start of the third. Thiem was sensing blood from the off in the stanza and struck to break at the first opportunity.
After consolidating, another break followed. At 4-0 down, the usually steely focus of Djokovic had been replaced by a look of dejection. The 32-year-old didn't appear to be all too comfortable out on court, either:
Thiem went on to win the set 6-3, and suddenly the favourite had a mountain to climb, with his form and fitness seemingly deserting him.
Yet from somewhere, Djokovic found extra reserves.
There was more pep in his play at the start of the fourth set. After applying pressure to his opponent's serve throughout the set, Djokovic broke to move 5-3 in front and then served it out to love, setting up a decider.
Per ATP Media Info, when matches go to five sets, Djokovic tends to prevail:
With momentum now firmly with him, it didn't take long for Djokovic to get an edge. There were some signs of weariness from Thiem in the third game, as consecutive mistakes gave Djokovic a break point and then the game.
Djokovic had to withstand some pressure on his own serve in the next game, but he was eventually able to consolidate. Despite the best efforts of a diligent Thiem, from there Djokovic served out the match in peerless style.