Custer led 31 laps en route to the win, the ninth of his career.
Justin Allgaier was second, Austin Cindric third, Justin Haley fourth and Chase Briscoe fifth.
This was also an elimination race and four drivers were eliminated from the 2019 playoffs: John-Hunter Nemechek, Justin Haley, Ryan Sieg and Brandon Jones.
The final stage went green on Lap 98/200 with Cindric in control, but Briscoe quickly moved into the race lead.
The run went long and so, green-flag pit stops became a factor. Gragson kicked them off with just about 40 laps to go.
Race leader Briscoe would pit with 32 laps remaining, but a caution soon after would change everything.
Dillon Bassett spun while trying to enter the pits, forcing a yellow flag while Nemechek was making his way down pit road for his own stop.
Only Custer, Haley and Michael Annett remained on the lead lap. Allgaier was the free pass and Briscoe, like several others, was forced to take the wave-around.
This set up a 15-lap sprint which was abbreviated by a three-car incident at the back of the pack.
The race resumed with seven laps to go, but Allgaier had nothing for Custer as he would take the checkered flag an even second ahead of the JR Motorsports driver.
The 200-lapper got off to a messy start with Tyler Reddick contacting the wall out of Turn 2 on the opening lap. Behind him, Harrison Burton spun and collected Joe Gibbs Racing teammate Brandon Jones. The incident effectively ended Jones’ 2019 title hopes.
Things went from bad to worse for the JGR outfit with Christopher Bell forced onto pit road with no fuel pressure. He returned to the race, but 14 laps down.
Nemechek got into the back of Mike Harmon, sending the No. 74 spinning for the second caution of the day.
Custer was in hot pursuit of Allgaier for the stage win, but could not quite get there. Allgaier would take the stage win ahead of Custer, Cindric, Zane Smith, Haley, Noah Gragson, Briscoe, Sieg, Nemechek and Michael Annett.
Custer would lost a plethora of spots on pit road, falling outside the top-ten before the start of the second stage.
It was a very different story for Stewart-Haas Racing teammate Briscoe, he charged from the back of the field to a position inside the top-five.
The stage was much cleaner than the first with no yellows and Allgaier easily able to take yet another stage win. He was followed by Cindric, Briscoe, Gragson, Custer, Smith, Nemechek, Haley, Annett and Sieg.