The Ford driver Posted his second round victory of the year in round seven at Queensland Raceway yesterday.
Winterbottom won races two and three after finishing second in race one on Saturday to secure the overall round win from Holden's Russell Ingall and Ford's James Courtney.
The Ford Performance Racing driver now holds a 122-point lead over defending V8 champion Garth Tander in the series, with the Holden driver fourth on the weekend.
Winterbottom was flawless all day yesterday, setting up his triumph by surviving a race two crash-fest to win the middle peg of the three-race sprint round.
He got the better of fellow Ford driver and Saturday's race one winner Courtney off the grid and also won the battle of the pitstops.
Then Winterbottom held off Ingall at the start of race three and didn't give anyone else a sniff to close out the victory.
Ingall, with a second and two thirds for the weekend, finished second overall to post his best result since moving to the Supercheap Auto team at the start of this season.