Sunday at the Island changed all that, the Spaniard converting his fourth straight pole position at the Australian Grand Prix into a hard-fought victory - and with it, putting himself in the box seat to win his fourth MotoGP world championship in his first five years in the category next weekend in Malaysia.

Marquez came to Australia with a slender 11-point championship lead after being beaten by Ducati's Andrea Dovizioso in a frantic head-to-head fight at last week's Japanese Grand Prix, but the Honda rider's sixth win of 2017, combined with Dovizioso finishing a season-worst 13th, saw Marquez extend his championship lead to 33 points with a maximum of 50 remaining in the final two races of the season at Sepang and Valencia. Game, set, and almost match.

Marquez's victory, after he'd topped the timesheets in all but one on-track session in every weather condition imaginable over three days at Phillip Island, didn't come easily. The Spaniard was ambushed into the first corner by the typically fast-starting Australian Jack Miller, and was embroiled in a frantic eight-bike fight for the podium places that raged until the final five laps, when he was finally able to break away.

Marquez crossed the line 1.7 seconds ahead of Valentino Rossi (Yamaha), the six-time Phillip Island winner surging through the field from seventh on the grid. Rossi's teammate Maverick Vinales stole the final podium position on the line from dynamic French rookie Johann Zarco, Vinales edging his Yamaha stablemate by 0.016 seconds.

Miller, racing just three weeks after fracturing his right tibia in a training accident near his European home base of Andorra, unexpectedly led for the opening five laps before fading to seventh, finishing just five seconds from the victory after qualifying an equal career-best fifth on Saturday.

Marquez, whose exuberant post-race celebrations went up a notch when he realised where Dovizioso had finished by stealing a look at a trackside big screen on his way back to the pits, knew that he'd gone a long way to becoming a four-time MotoGP world champion by the age of 24.

"'Dovi' was struggling a little bit this weekend, and I was feeling really good," he said.

"In the race, I was just waiting, waiting, and then I push hard for three or four laps. The bike was amazing."

Like Australian Casey Stoner before him, whose retirement in 2012 opened the door for the baby-faced Marquez to join the crack Repsol Honda squad, the sweeping curves of the seaside Phillip Island layout mesh perfectly with the Spaniard's all-action style; unlike Stoner, who won six straight times at home from 2007-12, Marquez has rarely been able to make his dominance count on race day.

Disqualified while running at the front on his Australian MotoGP debut in 2013, Marquez crashed out while leading in Australia in 2014 and again last year, his win in 2015 a rare reward for his mastery of one of the world's toughest tracks. Sunday's victory, which came after he dropped to fourth place 10 laps from home, was even more crucial given Dovizioso's Island misery continued.

The 31-year-old Italian has enjoyed the best season of his career in 2017, winning five Grands Prix to emerge as an unlikely title contender, and twice having the measure of Marquez in last-lap battles in Austria and Japan. But Dovizioso never figured at the front on Sunday, a heavy crash in final practice before qualifying on Saturday denting his confidence and seeing him qualify just 11th.

Running wide at the blindingly quick Doohan Corner at Turn 1 on the second lap dropped Dovizioso to 20th, and while he made his way back through the midfield, he relinquished places to fellow Ducati rider Scott Redding and Marquez's teammate Dani Pedrosa on the final lap to score just three world championship points. In 10 MotoGP appearances at the Island, Dovizioso has managed just one podium finish, a third place in 2011.

While seventh for Miller wasn't his best result of the season - the Townsville tyro finished sixth in wet races at the Dutch TT and in San Marino - it was by far his most convincing performance of the year, the 22-year-old featuring in the top 10 on the timesheets in every on-track session, and scoring nine world championship points to surpass his 2016 season total of 57 with two races remaining.

Phillip Island MotoGP TOP 10

1. Marc Marquez (ESP-Honda) 40min 49.772sec
2. Valentino Rossi (ITA-Yamaha) 40:51.571
3. Maverick Vinales (ESP-Yamaha) 40:51.598
4. Johann Zarco (FRA-Yamaha) 40:51.614
5. Cal Crutchlow (GBR-Honda) 40:53.617
6. Andrea Iannone (ITA-Suzuki) 40:53.643
7. Jack Miller (AUS-Honda) 40:55.391
8. Alex Rins (ESP-Suzuki) 41:01.980
9. Pol Espargaro (ESP-KTM) 41:06.023
10. Bradley Smith (GBR-KTM) 41:06.034

He wins #TheIslandBattle: Part Two! ????????#AustralianGP pic.twitter.com/TusKTixtmB??? MotoGP??????????????? (@MotoGP) October 22, 2017