The Movistar Yamaha rider crossed the line more than two seconds ahead of Ducati's Andrea Dovizioso, with Repsol Honda's Marc Marquez and Lorenzo's Yamaha teammate Valentino Rossi finishing third and fourth, respectively.
"I was surprised how fast my pace was towards the end of the race," Lorenzo later admitted. "I was sliding so much, but at the same time I was very smooth and concentrated and made no mistakes."
The race was intriguing rather than dramatic, but offered several pointers for the rest of the season.
Ducati's Andrea Iannone led early on in a sporadically stomach-turning battle with teammate Dovizioso.
The Italian factory bikes' sheer grunt on the home straight was impressive, and both looked set for podium finishes -- had Iannone not crashed out on the sixth lap. While Iannone laid sprawling on the gravel, the race settled down.
Marquez, who had slipped back to sixth after a poor start, provided a brief moment of anticipation as he arrived behind Rossi, but the Italian was unable to prevent his nemesis from passing him with relative comfort.
Lorenzo eases ahead
Lorenzo took the lead from Dovizioso on lap nine and, as fans have seen so often in the Majorcan world champion's career, gradually eased ahead.
Marquez briefly occupied second place after a thrilling pass on the remaining Ducati, but again the Italian bike's superior power took hold and Dovizioso was able to reclaim his spot.
Dovizioso was clearly delighted at his strong showing. "Starting off the season like this is a dream. I am really happy," the popular Italian told reporters after the race.
"We are only at the start, and maybe this won't be the real situation throughout the season, but we have an excellent base that makes us confident for the upcoming races."
Marquez too was delighted with a top three finish, particularly after a challenging winter for Honda.
"Just two weeks ago we were one second off the pace compared to the other guys on the podium," he said.
The Catalan also highlighted the power of Dovizioso's Ducati. "Whenever I got close, I'd lose him again ... I tried again in the last corner but it wasn't possible. I hope that the circuits coming up on the calendar favor us a little more."
Rossi signs, Lorenzo waits
Off the track, Rossi signed a new contract with Yamaha, taking him to the end of the 2018 season.
Lorenzo, meanwhile, has yet to re-sign with the team. An offer
is on the table, but Yamaha have admitted the star may leave for Ducati.
Elsewhere, Tech3's Bradley Smith announced that he will be joining KTM next year, as the Austrian factory enters the premier class for the first time.
The next race is in Argentina on April 3.