Australian MotoGP star Jack Miller has ended up indulging in his familiar 'shoey' celebration after earning his second podium place of the weekend at a rough-and-tumble Spanish Grand Prix.

The Queensland rider, fresh from finishing third in Saturday's sprint race, repeated the position 24 hours later in a dramatic main race as he demonstrated that he could be force in the championship race this year with his new team, Red Bull KTM.

Miller was involved in some terrific close-quarter racing on the celebrated Jerez circuit, even enjoying a spiky mid-race duel with his old Ducati teammate, world champion Francesco Bagnaia, who went on to take the chequered flag first and return to the top of the championship standings.

It all left the 28-year-old Townsville rider Miller taking his customary swig of champagne from his racing boot before throwing it into the laughing crowd below at the Jerez circuit.

He had been left delighted about his best weekend yet with his new team, who proved with his teammate Brad Binder finishing second after also winning Saturday's sprint race that KTM have the pace to prove the doubters wrong and win the title this year.

Miller had been eased out by the powerful Ducati factory team at the end of last season, with widespread predictions that he would struggle with his new outfit - but it looked anything but demotion over the weekend as the Australian qualified second and then finished third in both races.

Fifth in the championship last year, Miller is now lying fourth this season. Bagnaia has 87 points, with previous leader Marco Bezzecchi, who crashed with seven laps left, on 65, Binder on 62 and Miller now on 49.

"Stoked with the weekend, how it turned out," said Miller.

"If you'd said you'd pictured me in this position of being on the podium now this early on in the season, I'd have thought you were lying - but once we've started making some headway in development and the direction we've wanted to go with the bike, it's been phenomenal."

South African Binder had an even better weekend than Miller, having a fantastic last-lap dice for victory with Bagnaia before the Italian repelled his best efforts in a thrilling finale.

Bagnaia had earlier also been forced to drop a position by race control after moving up to second when he nearly knocked Miller off his bike while attempting an overtake that left the Australian gesturing angrily.

"I waved my arm at him and I was good to go," said Miller.

"Whether he deserved the penalty or not, I don't know, but we're asking for consistency and fairness."

The race had to be restarted after Yamaha's Fabio Quartararo and RNF Racing's Miguel Oliveira crashed on the opening lap, with Miller left frustrated because he'd taken a powerful lead at the start.

"After the red flag, I had to come back, regroup and start again. I had to work hard for that one, it was a long race," Miller shrugged.

"Brad rode awesome, Pecco (Bagnaia) rode awesome, there was some nice clean, fun racing there, super happy to be a part of it.

"It's an amazing feeling. A lot of people doubted us at the start of this one but we were ready and hopefully we can stay at the top."