Cameron Waters has denied New Zealand driver Shane van Gisbergen a 12th Supercars win of the season in an enthralling Townsville SuperSprint finale on Sunday.
Waters' run to victory was aided by a mid-race safety car following an accident for Macauley Jones.
Van Gisbergen, who claimed the lead from Waters on lap five, tried in vain to overhaul him in a 15-lap dash to the end.
It marked a second win in as many days in Townsville for Waters, who claimed the race 17 win on Saturday.
But he had to work hard for today's victory, holding on by less than a second to claim a second win in as many days, his third of 2021 and the fifth of his career.
Van Gisbergen had earlier charged to victory in race 18 - his 11th win of the season and eighth at the Reid Park Street Circuit.
The series leader claimed the lead through the pit sequence over Red Bull Ampol Racing teammate Jamie Whincup.
Whincup, who led from pole, opted for a three-tyre undercut stop but was undone by van Gisbergen's shorter two-tyre stop.
The pole-sitter had the better of van Gisbergen in the opening stint, eking out a 1.9sec lead after four laps.
The margin between the leaders dramatically narrowed to 0.4s by lap 16, with Whincup pitting on the following lap.
He took on three tyres and returned with clean air; van Gisbergen stopped on the following lap and took on two tyres.
By race's end, the margin between the two had blown out, with van Gisbergen taking the chequered flag 4.54 seconds ahead.
The New Zealander said he'd enjoyed the battle.
"It was awesome.
"It was a pretty cool battle, pretty tense. I'm sure there were some tight moments in the garage.
"But it was good fun."
Van Gisbergen, the defending champion, has extended his series lead over Whincup to 276 points.
- Supercars.com/RNZ