Dovizioso, who turns 35 on 23 March, began his career in 2000 racing 125cc bikes for Aprilia. He reached MotoGP in 2008 winning 15 races and finishing runner up in the championship for three straight seasons from 2017-19 with Ducati.
Based in Bologna, Italy, Ducati entered MotoGP in 2003, securing the riders' world title with Casey Stoner in 2007.
Oliveira followed up his maiden victory in Styria in August by taking the title at Portimao in what was his first race in the premier class in his home country.
Pole-sitter Franco Morbidelli won the race for this third victory of the season, but it was not enough to keep Mir from securing the title with one race to go
MotoGP 2020: Takaaki Nakagami grabs maiden pole in Teruel GP qualifying, championship leader Joan Mir in 12th
The 28-year-old Nakagami, who signed a new deal with Honda's satellite team earlier this week, posted a fastest lap of one minute and 46.882 seconds.
Alex Rins sliced through the field after starting 10th on the grid. He became the 8th winner in this season's ten races after the vacuum created by the early season injury to reigning champion Marc Marquez.
MotoGP 2020: Yamaha's Maverick Vinales wins Emilia-Romagna MotoGP to within one point of championship lead
The young Italian led by a second and a half at one stage and was still on course for a first victory for himself and Ducati-Pramac when he leant a bit too far unto a corner with seven laps to go and slid off.
MotoGP 2020: Franco Morbidelli wins maiden race at San Marino as Andrea Dovizioso takes championship lead
Yamaha SRT's Morbidelli, who started second on the grid, overtook pole sitter Maverick Vinales on the first lap and never relinquished his lead
Marc Marquez is the reigning MotoGP world champion. But he will not be able to make a bid at defending his title as he will be sidelined for another two to three months after fracturing his right arm in July's season opener.
Dovizioso avoided a string of crashes and narrow escapes notably that of Yamaha's Franco Morbidelli and Frenchman Johann Zarco.
As we head into the 2020 MotoGP season, the biggest question on everyone’s mind is – Can anyone challenge Honda's Marc Marquez?
MotoGP: Ducati rider Andrea Dovizioso expected to be fit for start of season after undergoing surgery on collarbone
Dovizioso sustained the injury on Sunday in a crash while competing in a motocross race at Faenza in northern Italy
MotoGP: After an early start to racing career, storied rivalry with Marc Marquez and five world Championships, Jorge Lorenzo bids farewell
Lorenzo has always been a name in the championship mix – with long and fierce rivalries against some of the greatest riders of his era including Casey Stoner, Dani Pedrosa, Valentino Rossi and Marc Marquez.
MotoGP 2019: Marc Marquez triple-crown winning season for Repsol Honda, Fabio Quartararo's breakout year and other talking points
Honda Repsol's Marc Marquez has won 12 races and the gap to his closest competitor in the points standings is a staggering 151 points
MotoGP 2019: Marc Marquez plans to use Valencia GP as test drive for next season; Jorge Lorenzo retires from professional racing
A MotoGP season dominated once again by Marc Marquez rolls to a close in Valencia this weekend with a fond farewell for former champion Jorge Lorenzo, who announced his retirement on Thursday
MotoGP 2019: Saturday qualifying cancelled ahead of Australian MotoGP as fierce winds cause havoc on Phillip Island
Phillip Island, known for its fast corners and long straights, is a favourite among MotoGP stars, but is also renowned for notoriously unpredictable weather
MotoGP 2019: Maverick Vinales upstages newly-crowned world champion Marc Marquez in Australian Grand Prix practice
Maverick Vinales upstaged world champion Marc Marquez by setting the quickest time during Friday's practice for the Australian MotoGP, as French rookie Fabio Quartararo sat out the second session after a spectacular crash.
MotoGP world champion Marc Marquez won the Japan Grand Prix on Sunday to notch his tenth victory of the season and third win on the circuit in four years.
MotoGP world champion Marc Marquez will eye his tenth win of the season after snatching pole position on Saturday in Japan.
MotoGP 2019: Repsol Honda's Marc Marquez underlines greatness, pulls off near perfect season to claim sixth title in seven years
Marc Marquez has pulled off a near-perfect season to claim the crown while dominating the rest of the grid and stamping his masterclass all around.