Perfect Piastri puts McLaren in driving seat
The Australian bossed practice and qualifying, and then produced a controlled drive under floodlights in Sakhir to follow up his success in China last month.
Teammate Lando Norris was being characteristically hard on himself after a qualifying session that left him starting in sixth.
A brilliant start in Sunday's nocturnal dust-up in the desert jumped him up to third, and despite a five-second penalty for positioning his car out of place on the grid, he secured a valiant third, with only George Russell's Mercedes denying a famous McLaren 1-2.
The result lengthened McLaren's lead in the constructors' championship. In the drivers' title race, Norris leads his teammate by only three points, with Max Verstappen slipping to third, a further four points away.
Red Bull left Bahrain looking for answers on their problematic car after Verstappen had to settle for sixth.
McLaren face a welcome but nonetheless potentially complex question of how to deal with two talented teammates battling for the same prize.
McLaren chief principal Andrea Stella's man-management skills could be tested to the full over the next 20 races.
For now, the papaya team owned by Bahrain's sovereign wealth fund, are enjoying the moment, not that Piastri plans to overindulge in the celebrations.
"I'm sure there's going to be a hell of a party! I'm not going to get involved, because I've got to race again next week (in Saudi Arabia)" said the man from Melbourne.
"I'm very proud of what I've done this weekend and proud to do it here in Bahrain as well. It's obviously a very important race for us, given our ownership.
"It's never been a track that's been kind to us, so it's great to finally get the first win for the team in Bahrain." he said after McLaren finally clicked in the Gulf kingdom at their 21st attempt.
'Right on the limit'
Norris was more measured.
"An up and down race today," he said.
"Some frustrating mistakes but still plenty of positives to take away with a strong points finish for the team in Bahrain."
"It was a really good race throughout, everyone pushing hard, right on the limit, which is always fun to be part of.
"Congratulations to Oscar and the whole team for today's result. I'll now keep my head down and work hard as we head to Saudi Arabia next weekend."
Stella praised the backing the team has received from Bahrain - through good times and bad.
"When we were building the team and not achieving the results we are seeing now, they were patient and gave us the resources we needed to set out on our current trajectory," he said.
"Oscar drove pretty much the perfect weekend. He was very solid in each session, every situation, and took the car to a deserved victory.
"Lando, starting P6, was always going to have to work hard this evening, and a five-second penalty made his job even harder – but he put in a very strong performance and ensured we get to celebrate a double podium finish, which is important for both Championships.
"I hope everyone will be enjoying the victory this evening."
Everyone except Piastri, who if he is true to his word will be getting some shut eye in preparation for Jeddah's Corniche circuit on the Red Sea next week.