Chaz Mostert admits to feeling “defeated” after turning pole position and a long-time effective lead into a finish of sixth in Race 3 at the Penrite Oil Sandown SuperSprint.

Mostert dropped to fourth off the start but appeared to be in an enviable position at the halfway mark thanks to an undercut.

With 19 laps down and 17 to go, the Walkinshaw Andretti United driver had an advantage of almost four seconds over early leader Tickford Racing’s Cameron Waters.

However, Mostert’s former team-mate ran him down and, to make matters worse, he gave up two more spots as he tried to salvage something from the brouhaha that unfolded with three laps remaining.

Mark Winterbottom and Anton De Pasquale got past on Laps 35 and 36 respectively, consigning the #25 Mobil 1 Appliances Online ZB Commodore to sixth all told.

“Obviously the wrong way today,” he said of pitting 11 laps earlier than Waters, another eventual podium finisher in Jamie Whincup, and also Winterbottom.

“Just disappointed; to start off pole and go back to finish sixth and struggling at the end with nothing to fight for, I feel a bit defeated today.

“[I am] looking forward to probably getting some dumplings tonight, and a nice cool shower, and come back fresher tomorrow.”

Asked to elaborate on exactly why he was so dejected, Mostert believed WAU had failed to correctly anticipate how their rivals would respond to the relatively early stop, which had put him into clear air.

“A number of things: the start, probably the wrong strategy compared to the rest of the field…” he explained.

“We probably read it a little bit wrong. We thought people would dive in early and we were about the only one early, so obviously everyone read the other book.

“It’s the way the game is; sometimes it works, sometimes it doesn’t, and today it just didn’t work out for us.”

At the other end of the spectrum, Shane van Gisbergen, who broke his left collarbone in a mountain bike accident a fortnight ago, hauled his way from 17th on the grid after a qualifying shocker to continue his unbeaten start to the 2021 Repco Supercars Championship.

Mostert paid tribute to the Triple Eight Race Engineering driver after the stellar comeback, while admitting he did not have the car pace of van Gisbergen’s #97 ZB Commodore.

“Not quite as quick as Gizzy,” he admitted.

“To come from the back of the field and to win that race in the state he is, congratulations to him and his team.

“I want to go and try to chase him tomorrow.”

Mostert retains second in the championship, albeit at an expanded, 60-point deficit to van Gisbergen.

It could have been even higher, had the 28-year-old not made history as the first driver to collect the five bonus points for setting the fastest lap.

Qualifying sessions for the next two races of the season take place back-to-back tomorrow from 10:30 local time/AEDT.