In a thrilling 160-lapper at the World Centre of Racing that came down to a green-white-chequered finish, van Gisbergen narrowly missed out after being mired in a last-lap crash.
Van Gisbergen took avoiding action and spun on the back stretch, and was ultimately classified 27th.
“One night doesn’t sum up our year, I guess,” said van Gisbergen.
“We haven’t been good enough, but it’s been cool to be close. A shame we’re not in it.
“Bits of it were good,” he said of his season.
“As a team we’ve obviously struggled. I’m proud that I’ve been able to match my teammates on the ovals.
“I think I’ve stepped up this year, but obviously you want to be in that Chase and didn’t make it.”
The overtime finish was triggered by a vicious crash for Carson Hocevar, whose #77 Spire Motorsports Chevrolet Camaro got loose before shooting up the track.
Erik Jones was left with nowhere to go and ploughed his #43 Legacy Motor Club Toyota Camry into the back of Hocevar.
Ty Gibbs was another innocent casualty, who had to take evasive action and spun his #54 Joe Gibbs Racing Camry.
At the time of the yellow, van Gisbergen was running 12th. The team feared he did not have enough fuel and elected to pit and take four tyres.
Van Gisbergen had been urged for the duration of Stage 3 to save fuel, but didn’t do enough to have the fuel in hand for the final few laps.
Trackhouse Racing crew chief Stephen Doran told van Gisbergen they made the right decision to pit under the yellow, which was an extended one due to the clean-up.
For the restart, van Gisbergen lined up 27th while his primary adversary Preece lined up second alongside Zane Smith.
Behind them, Ryan Blaney was third, Tyler Reddick fourth, Austin Cindric fifth and Daniel Suarez completed the top six.
Preece and Smith ran side-by-side through the first two turns before the #38 Front Row Motorsports Ford Mustang edge clear heading into the third turn.
Smith led the white flag with Preece second and fractionally ahead of Reddick.
The race-defining moment came when Smith got out of shape covering Reddick. He shot up the track and into the wall before coming down in front of the field.
Multiple cars were caught up in the melee and the race remained green until a second incident involving Ryan Blaney forced NASCAR to throw the yellow – and at that moment, Preece led.
The RFK Racing driver celebrated in style, performing a burnout on the front stretch before climbing atop his Ford Mustang.
“I’m just speechless right now,” said Preece.
“Those guys, that #60 group – we’re fighters, and when you put our back against the wall we swing hard.
“Two years ago there were a lot of keyboard warriors saying I was nothing but we just kicked their butts tonight.”
It’s the first NASCAR Cup Series points-paying race win for Preece and the first time he has made the Chase.
“It’s just a testament of how prepared these race cars are man,” said Preece.
“I’m a racer. I know what it takes to build speed. Every man and woman at RFK, thank you for giving me a rocket ship so I could go to the moon tonight.
“This is redemption.”
The NASCAR Cup Series Chase begins with the Cook Out Southern 500 at Darlington on September 7.