Harvick led 177 of the 337 laps during the event, and appeared on his way to an easy win after passing leader Ryan Blaney with 17 laps remaining.
Stewart-Haas Racing driver Kevin Harvick becomes the second driver to lock in for the Championship 4 at Homestead, joining Joey Logano.
Kyle Busch, a seven-time victor this year, and defending Cup champion Martin Truex Jr. are among the other six title contenders. He nearly won last week at Martinsville to ensure the chance for a championship repeat before Joey Logano's bump-and-run move on the last lap. Harvick, who started third, won the first stage and then followed it up with a win in the second stage.
Clint Bowyer, who started on the front row but had contact with Denny Hamlin on the first lap, was the only of the remaining title contenders outside of the top 10.
NASCAR says it erred in sending Jimmie Johnson's No. 48 auto to back of the field for the start of the race in Texas.More news: Hold tight for a Brexit breakthrough, May tells Cabinet
After restarting on the inside on two late-race restarts, Harvick went up top for the overtime restart and secured his eighth win of the season.
Harvick knew that Blaney would have to be ideal on the restart to beat him and once Blaney's left tires clipped the apron Harvick was off to his second career win at TMS.
Harvick was on the inside again for the next restart, before Blaney was able to get by him on the outside and into the lead. Harvick was already starting to rebuild his lead - it had been almost 4 seconds before the caution - when another yellow flag came out.
"That last restart I knew I needed to pick the top", Harvick said after the race.More news: Navy: Russian Jet Flies Dangerously Close to US Surveillance Plane
For the second week in a row, Martin Truex Jr. will have to start a Monster Energy NASCAR Cup Series race from the back of the field. "To start exactly where we were I think is a decent day. The only difference is there's one less spot available".
He passed inspection on the third try, and should have been able to start in his original qualifying spot.
There were several other cars also pushed to the rear for other issues, including the No. 48 of Jimmie Johnson after failing prerace inspection twice. He had qualified 23rd for his 600th start with Chad Knaus as his crew chief. "This is just one of a few calls that have been wrong due to that situation".
Johnson's teammate with Hendrick Motorsports, William Byron in the No. 24, was sent to the back of the field after three failed inspections.
In a race that produced a last-lap pass for the win, a record 13 cautions and an unmitigated disaster for favorite son Christopher Bell, Cole Custer moved past Tyler Reddick on the backstretch to win. Today he has earned his way in and he is going to attempt to be triumphant in another race and see what can be done on the home ground.More news: Tesla appoints Robyn Denholm to replace Elon Musk as chair