Elliott took the lead by staying out of the pits during a late yellow and hung on for his second career victory through two late restarts on the 1-mile oval.
It was a redemptive win for the Hendrick Motorsports driver, who lost the lead to Kyle Busch with a lap remaining a year earlier at Dover.
“Definitely makes it sweeter for sure,” said Elliott, who also rebounded Sunday from an uncontrolled tire penalty on his No. 9 Chevrolet.
Almirola’s lead evaporated with less than 10 laps remaining when teammate Clint Bowyer slammed the SAFER barrier after suffering a mechanical failure.
Almirola was the first driver out of the pits on four tires in sixth. His No. 10 Ford slipped up off the second turn after the green, causing him to tap Keselowski into a multicar crash that also collected Truex and Bowman.
“We’ve had so many opportunities and been so close and had the car to win and been in position and I don’t know, it just seems to not come through,” said Almirola, who was a half-lap from winning the Daytona 500 and also nearly triumphed at Chicagoland and New Hampshire. “I don’t know. I’m frustrated and mad and angry.”
Bowyer had been running in the top five for much of the race, including a stretch when all four Stewart-Haas cars occupied the top four spots.
“I guess we had another loose wheel, this sucks,” Bowyer said. “I’m so sick for Aric, that was his race to win.”
Seeking a clean sweep of 2018 at Dover (where he also won both stages and won in May), Harvick led a race-high 286 laps and was in control until a pit stop under green with 80 laps remaining. A valve stem on a left-side tire was knocked off, necessitating another pit stop under green to fix a flat.
Harvick returned to the track a lap down in 13th but caught a break when the first non-stage caution flag flew 20 laps later and put him back on the lead lap. He rebounded for sixth after narrowly missing the last pileup.
“We were just lucky there and wound up dodging and weaving and being in the right place,” Harvick told NBCSN’s Kelli Stavast. “I guess that makes up for the bad luck of losing the race with an absolute dominant car.”
The error by Harvick’s team came during a race in which all of the Big Three championship contenders made late mistakes. Kyle Busch and Truex also were hit with speeding penalties in the pits during the final 100 laps. Busch rallied for eighth.
Harvick’s dominance was evident early as only 14 cars remained on the lead lap after the first stage.
After falling out of the playoffs a week earlier because of a spin while gunning for a last-lap win at Charlotte Motor Speedway, Jimmie Johnson failed to take the green flag at the track where has a record number of victories.
The 11-time winner at Dover suffered a ball joint failure on the right front of his No. 48 Chevrolet on the pace laps and went to the garage for repairs. He returned on Lap 11 and finished 36th.
STAGE 1 WINNER: Harvick
STAGE 2 WINNER: Harvick
NOTABLE: The last two winners of the Round of 12 opener went on to capture the championship. Jimmie Johnson (2016) and Martin Truex Jr. (last year) each won at Charlotte Motor Speedway, which moved into the cutoff race of the Round of 16 this season.
QUOTE OF THE RACE: “After last fall, I was really making sure I didn’t make any contact, to be honest with you.” — Denny Hamlin on being outside of Chase Elliott for the final restart. Hamlin crashed Elliott while racing for the lead at Martinsville Speedway on an overtime restart in October 2017.
WHAT’S NEXT: 1000Bulbs.com 500 at Talladega Superspeedway, 2 p.m., Oct. 14 on NBC.