Fortune finally favored Australia's Daniel Ricciardo in the World Series by Renault as he won the sixth race in European championship filled with young drivers from around the world clamoring to make it to Formula One.

Ricciardo had been forced to start the fifth race at Monza in Italy on Saturday from the rear of the grid because bolts had been found to be loose on his car after he qualified on the front row.

At the previous two races at Spa in Belgium he finished only 10th and ninth because his car was not quite right after an earlier crash.

And he had had missed the first two races in Spain because he was required in Shanghai to drive a Toro Rosso F1 car in early practice at the Chinese Grand Prix.

On Sunday Ricciardo started from pole position at the famed high-speed Monza and had a thrilling battle with French youngster Jean-Eric Vergne, who like the Perth star is a member of Red Bull's elite junior driver development squad being groomed to race in F1.

Vergne crossed the finish line first after 28 laps at Monza but was given a 10-second penalty for cutting two chicanes, handing victory to Ricciardo.

After his bold drive from last to sixth on Saturday, the 21-year-old from Duncraig in Perth is seventh in the series for 3.5-litre Renault-engined open-wheeler cars.

However, he gives himself little chance of winning the title he came within two points of snaring last year because of missing the first two races and subsequent misfortunes.

His priority has become driving for Toro Rosso in the Friday morning F1 practice sessions at GPs, in which he has been as high as eighth fastest of 24 drivers including five world champions.

Vergne, who last year won the British Formula Three Championship that Ricciardo won in 2009, now leads the Renault series on 90 points and has signaled an appeal against the outcome of the latest race in which he was ultimately classified third.

American Alexander Rossi was promoted from third to second in Sunday's race and is second in the standings on 73 points, with Canadian Robert Wickens third on 71 points.

Ricciardo, seventh on 36 points, described his Monza victory as "an interesting and very challenging race".

"I had the lead into turn one, but I went in a little too deep and cut the chicane," he said.

"I then backed off in order to not make an advantage and Jean-Eric came alongside me and passed me into the second chicane.

"I was a bit faster than him in the first part of the race and it was very close on a couple of occasions, but I couldn't get the last little bit to get past him.

"Then about midway through the race I had a good run into the second chicane and dived to the inside on braking.

"We were side by side into the corner and Jean-Eric cut the second apex and kept going in the lead.

"I felt I should have had the position and he should have given up his advantage.

"In the last part of the race his pace improved and I couldn't really get close enough to attack him properly.

"It was nice to be awarded first place after the race, but it would have been good to be first across the line.

"It was a very challenging race, but at the end of the day the points are very welcome."