It was enough to please the Brazilian's Pramac d'Antin Team, but Barros himself felt Phillip Island was a missed opportunity.
"The team is happy but I'm not because I know that I could have done more," he said. "I started the race with a hard tyre, because we thought that the medium wouldn't last the entire race, but in the end I think I would have had a better racepace with the medium. Nowadays in MotoGP, if you don't have everything at 100% you are not able to fight with those ahead of you."
New team-mate Chaz Davies was less fortunate, being forced to retire with a technical problem on lap 13 of 27. The 20-year-old had risen from 17th to 14th - in front of Fiat Yamaha's Colin Edwards - in the early stages, before rear tyre problems emerged.
"I didn't have a good start, but I was able to make up some positions in the early laps and get into a good rhythm," said the Briton. "On the fifth lap, I started having problems with the rear and it became difficult to ride the Ducati. Unfortunately, by the 12th lap I also started having a technical problem with the bike and was forced to retire."