Aleix Espargaro said "this one's for Pecco" after winning a Catalunya MotoGP at Montmelo on Sunday marred by world champion Francesco Bagnaia's horrific crash.
Espargaro's Aprilia teammate Maverick Vinales took second with Jorge Martin completing the podium.
As Espargaro celebrated a dream double at his home race after also winning Saturday's sprint, Bagnaia was receiving medical attention in a local hospital.
The Italian Ducati star had set off from pole. He avoided a multi-bike pile up triggered by Enea Bastianini at turn one but at the next corner lost control.
Bagnaia was thrown violently over his Ducati's handlebars and into the air after a 'highside' in front of the chasing pack.
Brad Binder's KTM then ran over the 26-year-old's leg.
The series leader was conscious, and taken away to the track's medical centre in an ambulance, with the crowd clapping him.
He was later transferred to the local hospital where "tests revealed he had suffered multiple contusions, but no fractures", according to his team
"He will return to Italy this evening with the team," Ducati added.
Bagnaia's teammate Bastianini was also injured in the first lap mayhem.
He suffered a left ankle and hand fracture when triggering a domino-effect crash involving Alex Marquez (Ducati-Gresini) and Italian duo Fabio Di Giannantonio (Ducati-Gresini) and Marco Bezzecchi (Ducati-VR46).
- 'I'm speechless' -
"He needs an operation on his ankle and to speed up his recovery also on his hand in the next few days," Ducati said.
Espargaro's thoughts were with the stricken world champion.
"This win is for Pecco, luckily we've just heard it's nothing serious," he said.
Turning to his finest weekend in MotoGP he added: "I'm speechless.
"Thankfully nothing happened to us on the first lap.
"It was difficult in the wind. I thought I would not catch him (Vinales), but I waited and I did it."
For Espargaro this was a weekend of personal redemption after his embarrassing slip-up last year when he celebrated making the podium one lap too soon, eventually finishing fifth.
To remind him of the howler he wore a helmet on Saturday with the words "One more lap" written on it.
Vinales was buzzing after Aprilia's first 1-2 in motorcycling's fast lane.
"First and second Aprilia - I'm so happy," he said.
With Bagnaia missing, the track cleared of debris and oil, the race restarted for 23 of the scheduled 24 laps.
Vinales led early on from Martin and Espargaro, born a couple of kilometres from the track.
Espargaro was soon into second, chasing his factory Aprilia teammate, wit Miguel Oliveira racing third on a satellite Aprilia.
Binder had to pull out with tyre issues and the first thing the South African did was to go and check on Bagnaia's condition in the medical centre.
At the halfway stage Vinales had put daylight between himself and Espargaro as Martin took over third from Oliveira.
Espargaro threw everything at the leader setting up a thrilling conclusion to this 11th race of the season.
With four laps remaining Espargaro edged past his teammate and fellow Catalan for a popular win for the 70,000 home supporters.
In the world championship, Martin cut his deficit to Bagnaia to 50 points ahead of next weekend's San Marino MotoGP where Bagnaia will be hoping to make a quick return to continue his quest for back-to-back titles.