David Reynolds has taken the blame for his accident with James Golding, saying he "came unstuck due to my own stupidity".
Reynolds and Golding had charged into the top 10 in the early stages of the wet OTR SuperSprint finale.
It had been a particularly impressive drive from Reynolds, who started 25th and last.
However, Reynolds lost control on lap 15 at Turn 6 and rammed into the unsuspecting Golding.
Golding limped home 14th, with Reynolds suffering major front damage.
Reynolds lost four laps and came home 22nd, last of the classified finishers.
The Penrite Racing driver explained he simply fell off the "train tracks" and aquaplaned.
"I came unstuck due to my own stupidity," Reynolds told Supercars’ Cool Down Lap podcast.
"I got all fogged up… conditions got really bad towards the end before I crashed.
"I came around one lap, and I could see the wheel tracks.
"When it rains, everyone runs on the wheel tracks because it divides the water for the tyre to sit on.
"If you come off those wheel tracks, that’s when you’ve got no grip.
"As soon as I touched the brake, I was spinning out of control and smashed into the PremiAir car.
"I felt so bad, my car was destroyed."
It came after Reynolds raced to eighth in the first two races of the weekend.
Reynolds' damaged Mustang
The 2017 Bathurst winner retained seventh in the championship.
However, he was "gutted" over the incident, which came after a shocking qualifying.
Reynolds qualified 27th and last for the race, which became 25th after Thomas Randle and Andre Heimgartner were ruled out.
"I feel terrible for my boys," Reynolds said.
"The qualifying was so bad, and we were making up good positions.
"We could have been sixth, fifth, around there.
"That would have been awesome job from last.
"I’m just gutted for myself."