While four-time reigning champion Whincup isn't a part of the championship equation this time around, he said it was obvious how big Sunday's 200km race would be.
"It's a big 150-pointer coming up tomorrow," he said.
"It's the biggest day of the year as far as the championship goes."
Lowndes recognised he faces an uphill battle to steal the title but vowed to continue the battle.
"If we can keep winning races and keep the pressure on, who knows what will happen," he said.
"We learn today and we fight tomorrow."
Prodrive Racing executed its low-risk strategy on Saturday, with Winterbottom running home in seventh and fourth places.
It could have been worse for `Frosty', whose garage performed a 38-minute engine swap between qualifying and racing after he complained of a lack of power.
The Ford garage had other things to worry about, chiefly the dangerous rumble between Van Gisbergen and Reynolds that left their unlikely championship contender on the canvas.
Reynolds blew his top at Van Gisbergen's move, declaring the Kiwi "dead to me" after the 220km/hour incident placed him last in race one.
The Ford man recovered in Saturday's second sprint race to finish fifth, keeping alive his faint title hopes.
But the series now looks a two-car race between Winterbottom and Lowndes after he steered the No.888 to a record 10th win on the island.
There are a maximum 450 points left to play for, including the season-ending meet at Sydney in a fortnight's time.
Lowndes' record-breaking victory came off the grid, when he vaulted past Whincup and Volvo driver Scott McLaughlin on the front row into the lead.
V8 SUPERCARS RESULTS
RACE 31 RESULT
1. Craig Lowndes (Holden)
2. Jamie Whincup (Holden)
3. Scott McLaughlin (Volvo)
4. Shane Van Gisbergen (Holden)
5. James Moffat (Nissan)
RACE 32 RESULT
1. Jamie Whincup (Holden)
2. Scott McLaughlin (Volvo)
3. Craig Lowndes (Holden)
4. Mark Winterbottom (Ford)
5. David Reynolds (Ford)
CHAMPIONSHIP STANDINGS
1. Mark Winterbottom (Ford) - 2887
2. Craig Lowndes (Holden) - 2678
3. David Reynolds (Ford) - 2610
4. Garth Tander (Holden) - 2375
- AAP