Truex and Elliott had been dueling for the lead for most of the final stage with Harvick more than four seconds behind them. But when Truex got into Elliott, apparently because he mistakenly believed he had his rival cleared around the bend, Harvick swooped in to capitalize.

Elliott finished 20th, while Truex dropped to 22nd after getting a flat tire from their collision.

Austin Dillion shook off a slow start to finish second. Joey Logano crossed the finish line third.

Sporting News tracked live updates and lap-by-lap highlights from Sunday’s NASCAR race at Darlington. Follow below for complete results from the Cook Out Southern 500.

MORE: Watch today’s NASCAR race live with fuboTV (7-day free trial)

Darlington finishing order for playoff drivers

Lead changes: 18Leaders: 6Cautions: 7

NASCAR at Darlington results, highlights from Southern 500

10:06 p.m.: Kevin Harvick wins the Southern 500.

10:04 p.m.: Harvick leads with five laps to go.

10:03 p.m.: Elliott has dropped to 11th. That incident changed everything.

10:02 p.m.: Truex exits the scrum with a flat tire. He has to pit.

10:01 p.m.: The leaders push each other into the wall! Whoa.

9:59 p.m.: 15 laps to go. Truex has jumped ahead of Elliott. Harvick is a distant third.

9:52 p.m.: This marathon race is entering its last stretch. There are 30 laps remaining. Elliott leads Truex by less than a second.

9:39 p.m.: Caution for debris. Seventh yellow flag of the race.

9:23 p.m.: Truex continues to hold an advantage. He’s ahead of Kyle Busch by about three seconds.

9:09 p.m.: There are 100 laps to go in this race. Truex, Kyle Busch and Denny Hamlin make up the top 3.

9:08 p.m.: Debris on the track but the race stays green for now.

8:53 p.m.: Caution for John Hunter Nemechek.

8:50 p.m.: LaJoie is done.

8:46 p.m.: Not a great evening for this playoff newcomer.

8:40 p.m.: Truex wins Stage 2.

8:23 p.m.: Kevin Harvick is up to second place, but his team is worried about his tires. The rubber is showing wear.

8:18 p.m.: Back to green with 45 more laps in Stage 2.

8:10 p.m.: Caution out for Bubba Wallace.

8:06 p.m.: Kurt Busch temporarily takes the lead as others pit.

7:55 p.m.: Elliott rubbed the wall and has dropped to fourth. Truex still holds the lead.

7:44 p.m.: Ryan Blaney falls a lap behind.

7:30 p.m.: Martin Truex Jr. wins Stage 1.

7:17 p.m.: Keselowski will continue following the crash. The race is back to green.

7:08 p.m.: Caution. Keselowski makes contact with the wall.

7:01 p.m.: Denny Hamlin takes the lead midway through Stage 1.

6:34 p.m.: Elliott still leads through 25 laps.

6:28 p.m.: Denny Hamlin flirts with trouble.

6:24 p.m.: Chase Elliott is the early leader.

6:20 p.m.: The flag goes to green and the playoffs are officially underway.

6:10 p.m.: Engines fired.

6 p.m.: Pre-race penalties have been given out.

NASCAR race start time today

Date: Sunday, Sept. 6  Start time: 6 p. m. ET TV channel: NBCSN Live stream: NBC Sports Go | fuboTV (7-day free trial)

The green flag for Sunday’s NASCAR Cup Series race at Darlington will wave shortly after 6 p.m. ET, assuming there are no rain delays as there have been so often since NASCAR returned to live racing in May.

This start time typically creates a unique challenge for drivers at Darlington. The late-summer South Carolina heat makes for a slick race track that evolves as the day turns into night and the conditions get cooler. Mid-race adjustments will be key for that reason.

Darlington Raceway obviously has lights, so a weather delay could push the race into the late hours of Sunday and early hours of Monday.

Sunday night’s race is is one of the longest time-wise of the Cup Series season. It is scheduled for 367 laps (501.3 miles) and needs to reach the halfway point to be considered official in the event of weather issues.

MORE: Throwback paint schemes for Darlington race

NASCAR starting lineup at Darlington

Here’s the complete starting lineup for Sunday’s NASCAR race at Darlington: