Bagnaia made history in 2021 when he overturned a 91-point deficit to end a 15-year wait for Ducati's second world title in MotoGP.
Dominant in the first half of 2023, Bagnaia led the championship by 66 points after the sprint in Barcelona only to crash out of that grand prix and suffer injury in a horrible collision with Brad Binder.
Pramac's Jorge Martin was able to capitalise on this as he came into a purple patch, briefly overhauling Bagnaia in the standings by seven points after the sprint in Indonesia before losing it again in the grand prix.
The pair came into the finale split by 14 points, but Bagnaia won the Valencia GP after Martin crashed with Marc Marquez.
Bagnaia's advantage over Martin at the end of the season stood at 39 points as he became the first rider since Marc Marquez in 2019 to successfully defend their crown.
Here are the key moments of Bagnaia's 2023 season.
Portuguese GP – Round 1
After the problems of the pre-season the year before, which ultimately led to Bagnaia ditching the full 2022-spec Ducati engine in favour of a hybrid version more akin to the 2021 unit, 2023 couldn't have been more different.
A strong testing period on the GP23 gave way to an emphatic start to Bagnaia's title defence in Portugal at the start of the campaign, winning the first-ever MotoGP sprint race and fending off Aprilia's Maverick Vinales to scoop the grand prix.
A perfect 37 points signalled intent from Bagnaia that 2023 would be vastly different to the year before, where he was forced to overturn a hefty mid-season deficit to eventually take the crown.
Spanish GP – Round 4
Bagnaia remained quick throughout the Argentina and Americas weekends. But in the former, he struggled to sixth in the sprint before crashing while running a comfortable second in the grand prix.
And in America, he started on pole and won the sprint, only to crash while leading at the Circuit of the Americas in the grand prix. Blaming his Ducati for being too perfect, and thus too stable for him to be able to feel where the limit of the front-end was, Bagnaia rolled back on this at Jerez.
As old habits were clearly dying hard, a big weekend in Spain was a must. Coming through Q1 to qualify fifth, Bagnaia only just lost out in the sprint to KTM's Brad Binder before securing his second grand prix win of the season on the Sunday.
Crucially, it returned him to the top of the championship standings by 22 points over erstwhile leader Marco Bezzecchi – the VR46 rider having broken his win duck in Argentina.
Italian GP – Round 6
Just as things were looking up for Bagnaia, they came crashing down again at Le Mans.
A podium in the sprint, having qualified on pole, got his weekend off to a solid start. But a collision with Vinales in the grand prix led to his third non-score on a Sunday from the first six rounds and a crack in his foot for good measure.
It also put Bezzecchi, who won the French GP, back onto his tail at just one point adrift in the championship standings.
But at Mugello, on home soil for Bagnaia and Ducati, he turned out another champion's performance. Qualifying on pole with a new lap record, Bagnaia snatched sprint victory from Bezzecchi and Martin, then doubled up in the grand prix over the latter.
He extended his championship lead over Bezzecchi to 21 points, though now Martin was starting to close in at 24 behind.
Austrian GP – Round 10
After his Mugello double, Bagnaia lost out to Martin in the sprint in Germany and couldn't overhaul the Pramac rider in a thrilling dice for victory in the grand prix.
He responded at Assen with victory ahead of the summer break but scored nothing in a sprint for the first time in 2023 at a soaking Silverstone and had the grand prix win snatched from him on the final lap of the British GP by Aprilia's Aleix Espargaro.
The damage to his championship charge was minimal, in truth, his gap standing at 41 points heading to Austria as Martin's form wavered over the Dutch and British GPs.
Austria arguably marked the peak of Bagnaia's season. Qualifying on pole, he led every lap of the sprint to beat KTM's Binder by 2.056s, and did so again in the grand prix to score his fifth Sunday win of the season.
With Martin seventh in the grand prix having been awarded a long lap for triggering a Turn 1 pile-up at the start of the sprint, the damage Bagnaia inflicted was massive as his points lead increased to 62.
San Marino GP – Round 12
This was by no means Bagnaia's best weekend of the season, but it was hugely important in the defence of his championship.
The fact he even made it to Misano in the first place was an incredible feat, having suffered severe bruising to his right leg after being run over by Binder on the opening lap of the previous week's Catalan GP.
Fortunately, Bagnaia escaped serious injury and was able to race at Misano, finishing a respectable third in both the sprint and the grand prix.
Having been 66 points clear in the championship after his sprint victory in Barcelona, Bagnaia was now only 36 ahead of Martin after the Pramac rider's Misano double. But the damage could have been far worse had it not been for Bagnaia's determination.
Indonesian GP – Round 15
By this point of the campaign, Martin was on a high having done the double at Misano; won the sprint and finished second in the GP in India; then doubled up again in Japan.
Arriving at the Indonesian GP, Martin was just three points shy of Bagnaia and vaulted seven clear after winning the sprint while his factory Ducati rival could only recover from 13th to finish eighth.
In the grand prix, Martin was on course to dominate when he crashed late on leading by over three seconds. Bagnaia brilliantly worked his way through the order and went on to win the grand prix, restoring his championship lead to 18 points heading to Australia.
Australian GP – Round 16
Martin didn't look like he was going to let his Indonesian GP gaffe dent his confidence, as he proved once again as the rider to beat when the championship reached Phillip Island the following week.
Launching from pole, Martin was one of only a few riders to gamble on the softer rear tyre for the grand prix.
Once again breaking away by over three seconds, he looked on course to add to his grand prix victory haul for the season. But his soft tyre faded dramatically in the closing laps, and he would slump from first to fifth across the last tour.
Crucially, Bagnaia was able to leap up to second having tactically kept his tyres in check and ridden cautiously in the first half of the grand prix, knowing Martin would ultimately come back to him.
Extending his championship lead to 27 points, Bagnaia showed in Australia the mindfulness needed to win a world title.
Malaysian GP – Round 18
Martin's double victory in Thailand put him 13 points behind Bagnaia heading to Malaysia, but he had copped an official warning for riding underneath the minimum tyre pressure limit in Sunday's grand prix at Buriram.
This forced a more cautious approach from the Pramac squad on tyre pressures at Sepang, something Bagnaia took full advantage of.
While Martin had the edge in the sprint, Bagnaia pulled clear in the grand prix after their battle for third in the early stages before streaking over six seconds clear to secure the podium.
Bagnaia did end up with an official warning for breaking the tyre pressure rule, however, setting up a precarious end to the championship race. However, the 14-point lead he left Malaysia with was enough to give him his first match point in the penultimate round in Qatar.
Round 19 – Qatar
But Bagnaia's first match point in Qatar didn't go to plan. Rear tyre issues in the sprint saw him finish fifth, while Martin took an emphatic victory.
The championship gap between them was trimmed to seven points. But in the grand prix, tyre issues impacted Martin and sent him tumbling down the order to 10th.
Bagnaia led for much of the contest, before ultimately losing out to Fabio Di Giannantonio – and almost crashing into him moments after losing the lead down into Turn 1.
Surviving his late scare, Bagnaia came through to finish second and open up the points gap to 21 heading to Valencia.
Round 20 – Valencia GP
Martin cut Bagnaia's championship lead down once more to just 14 points after winning the sprint while his rival was fifth, though the upper hand belonged to the factory Ducati rider still.
Promoted to pole after Maverick Vinales was hit with a grid penalty, Bagnaia took the holeshot in the grand prix as Martin leaped up to second.
Martin would run him close, but his hopes faded when he ran off at Turn 1 after outbraking himself on lap three.
On lap six, Martin crashed out in a clash with Marc Marquez which meant the title was Bagnaia's. And for good measure, so too was a seventh grand prix win of the season.
