Sprint winner Jorge Martin got the holeshot from pole position on his Pramac Ducati, but Bagnaia got an even better launch from fifth on the grid to slot into second position.
Eager not to allow Martin to run away at the front, Bagnaia wasted little time in making a move on his 2023 title rival, throwing his factory Ducati up the inside into Turn 4 to snatch the lead straight away.
While Martin kept the pressure up on Bagnaia early on, he soon got embroiled in a long battle with the KTM of Brad Binder, giving the Italian rider some breathing space to manage his tyres.
By lap 11, the two-time champion was over a second clear of the chasing pack and, although Binder was able to bring the gap down to under a second, Bagnaia was able to extend his advantage again en route to his 19th MotoGP victory.
Binder and Martin engaged in a long scrap for the best-of-the-rest, trading positions at a number of occasions and also bringing Marquez and Pedro Acosta into play in the battle for second.
In the end, it was Binder who emerged on top in that battle, the KTM rider sealing the position when Martin ran wide at Turn 1 on lap 11.
Martin ended up 0.5s down at the finish after picking up his ace on the penultimate lap of the race.
Marquez enjoyed a similarly close battle with Tech3 GasGas’s Acosta, with the KTM-backed rookie pulling off a stunning move at Turn 1 at the start of lap 12 to move into fourth position.
But Acosta ran wide through Losail’s tight sequence of corners just two laps later, allowing Marquez back through into fourth - a position the eight-time world champion carried to the finish to round off a promising maiden weekend on the Gresini Ducati.
Source: Autosport