Motorsport: Brendon Hartley 15th at Abu Dhabi Grand Prix

Toro Rosso driver Brendon Hartley during the Abu Dhabi Formula One Grand Prix at the Yas Marina racetrack. Photo / AP

Kiwi driver Brendon Hartley has finished 15th in the season ending Abu Dhabi Grand Prix for Torro Rosso after failing to finish races in Mexico and Brazil.

Having failed to finish the two previous races in Mexico and Brazil, Hartley drove impressively after struggling in qualifying and starting at the back of the 20-car grid.

It is the New Zealand driver's second completed race after joining Toro Rosso near the tail-end of the season.

He was 13th in his debut drive at the United States Grand Prix before engine problems at the next two events.

Sunday's drive left him one place off French team-mate Pierre Gasly, with whom Hartley will contest the entire 2018 championship.

Their combined efforts weren't enough to keep Toro Rosso sixth overall in the team standings and they dropped one place.

Hartley climbed steadily in the early part of the race, reaching as high as 14th as rivals either struck problems or pitted.

He engaged in a duel for 13th to 15th over the second half, eventually finishing behind Haas driver Kevin Magnussen and Sauber's Pascal Wehrlein.

Valtteri Bottas has won the race ahead of his world champion Mercedes teammate Lewis Hamilton.

The Finnish driver comfortably secured the third win of his F1 career, all coming this season since joining from Williams. It was his 22nd career podium and 13th with Mercedes.

"It is a really important win for me after having a pretty difficult start to the second half of the year," said Bottas, who had a mid-season slump that affected his confidence. "We Finns don't show much emotion but it doesn't mean we don't have any. I am so happy. There has been so much support. I can't show it too much but I feel good."

Bottas in third place overall, 12 points behind Vettel and 58 behind Hamilton.

"Hopefully better next year," said Bottas, who has another year on his Mercedes contract and will be under pressure to improve.

With his fourth world title already secure, Hamilton had no need to chase the win. He finished 4 seconds behind and did not get close enough to attack.

"Valtteri did a great job to hold me off," Hamilton said. "Congratulations to him."

The race started at 5 p.m. local time with the sun setting on the desert setting of the Yas Marina circuit and finished under floodlights.

Bottas started from pole for the fourth time this season and assuredly held the position into the first corner.

Sebastian Vettel, who won the last race in Brazil, finished 20 seconds behind him in third place.

"After three or four laps, I just couldn't go any faster," Vettel said. "Congratulations to Lewis on his season. He was the better man. I hate to say it but he deserved it."

Vettel's Ferrari teammate Kimi Raikkonen was fourth and also moved up to fourth in the standings.

Hamilton clinched the world title — his third with Mercedes — in Mexico two races ago when he ended Vettel's fading hopes.

Red Bull driver Max Verstappen finished fifth while teammate Daniel Ricciardo retired, dropping from fourth to fifth in the standings.

The other wins for Bottas this season came in Russia and in Austria — also from pole — and he performed spins on the track to celebrate. Hamilton, who won nine races this year, did the same.

Bottas made a clean start while Hamilton held off Vettel, who locked his left front tire angling into the first corner.

The 5.6-mile track is difficult to overtake on and the top grid positions were easily held.

After 21 of 55 laps Bottas was 2.5 seconds clear of Hamilton and eight ahead of Vettel, who was the first of the trio to pit for new tires. Bottas did one lap later, leaving Hamilton briefly in front.

At much the same time, Ricciardo retired, leaving his stranded Red Bull on a patch of grass as he hitched a lift back to the team garage on the back of a scooter.

It was the third time in four races — and sixth in 20 this year — that the Australian driver has failed to finish.

Bottas regained the lead when Hamilton came in for his tire change on lap 25.

"I was really managing the pace and the race," Bottas said. "The last five laps I started to go a bit quicker."

Renault driver Carlos Sainz Jr. joined Ricciardo in the paddock after an apparent steering issue ended his race with about 20 laps to go.

Nico Hulkenberg was sixth — despite a five-second time penalty early on for cutting a corner in his Renault — and placed ahead of Force India drivers Sergio Perez and Esteban Ocon. Two-time F1 champion Fernando Alonso got ninth in McLaren's last race with the under-performing Honda engines before switching to Renault as its supplier for 2018.

Veteran Brazilian driver Felipe Massa, the 2008 F1 runner-up to Hamilton, finished 10th in his last race before retiring.