After racing it safe in Races 15 and 16, Winslow, of Fujitsu Racing with Threebond JA Motorsport, ruled the race in 19 minutes, 21.48 seconds, seven seconds ahead of compatriot Charles Hollings’ 19:28.241.
Winslow actually clinched the overall title as early as Saturday after settling for podium finishes in Races 15 and 16.
In Race 15, he contented himself with a third place finish behind Filipinos Dado Peña, who zoomed from the back of the pack to the top of the heap, and Tyson Sy before emerging second to fellow Briton Charles Holling in the collision-marred Race 16.
He then poured it all on.
"Now I’m not fighting for points in the championships, I kind of realized and pushed and enjoyed my race unlike yesterday when I was a little bit tense," said Winslow, who had six first place finishes, all in Sentul, Indonesia, heading into the RP leg.
After running Saturday into misfortunes that enabled Sy to overtake him at second place, Ali Jackson of Ireland bounced back strong by finishing third in Race 17 to regain the No. 2 spot with a 199 points, 11 points ahead of Sy.
Winslow has 262 points with a round left.
In contrast, Sy needed to stay ahead of Jackson to keep his post but had trouble in his car’s left rear end tire that slowed him down.
"We’ll be watching out (for Sy), since it’s been a trend, people coming from the back to finish in the podium," said Jackson. "We’ll try to stay ahead of him as much as possible, I’ll push hard so he can’t catch me."
Peña, who also finished third in Race 16, fared even worse, losing control of the steering wheel right in the first lap.
"Just lost steering after making contact with another car on the first corner," rued Peña. "I still managed to take a few turns and pass Moreno (Soeprapto) but eventually totally lost steering."
Meanwhile, Hollings, of Team Goddard, bucked a slow start with a steady finish to rule the accident-marred Race 16, besting countryman Winslow and Peña.
The event is backed by PLDT myDSL, Yokohama , Big Shot Billiards, Mossimo, Oky Enhanced Water, Lima City Hotel, Asti Cinzano, Samsung, Silver City Automall, Viva Mineral Water and Powerade.
Hollings, who is a veteran karting and F3 campaigner back home, set the best time in the qualifying to clinch the starting grid in the 14-car race but couldn’t start well to fall several notches behind the launch.
He kept his cool and plodded on until finding the right opportunity to overtake Sy, Jackson and Winslow.
"These cars are different and I kind of struggled in the takeoff. I was ready to take third because the two cars up front were really quick, but somehow they had this accident and I was all alone in the front," said Hollings.