The weekend saw Mostert close to within 174 points of Winterbottom with a trio of podium finishes that included two victories.
Mostert has scored a stunning 10 pole positions from the first 23 qualifying sessions of the season, compared to just one for Winterbottom.
Following his latest win, Mostert admitted that he has started to believe that he can win this year's title, but stressed the need not to look too far ahead.
“Everyone's goal is to try and get as many points as they can to win the championship,” he said.
“This year for me I thought it was pretty unrealistic, but after a good weekend here, (if we) have a good run for the enduros, we never know where we'll end up.
“I'm just thinking about it one round at a time. I'm pretty simple-minded type of guy if anyone hasn't worked that out yet, and just take every race as I can.”
The upcoming three-event Pirtek Enduro Cup will see Mostert teamed with Dunlop Series leader Cameron Waters, while Winterbottom continues with experienced hand Steve Owen for a second year.
What do you think? Is Mostert the new favourite for the V8 Supercars title? Vote now in this week's Pirtek Poll.