Key notes: The Lucas Oil Late Model Dirt Series kicks off a Labor Day doubleheader weekend with Saturday’s 50-lap, $15,000-to-win River Days Rumble at Portsmouth Raceway Park. … Daulton Wilson of Fayetteville, N.C., earned a flag-to-flag victory in Friday’s Boone Coleman Gator 50, collecting $7,500 and his first career American Late Model Iron-Man Series win. Wilson led the opening 43 laps last year before losing an engine and handing the Coleman Gator 50 triumph to Ricky Thornton Jr. … Series points leader, Thornton, of Chandler, Ariz., is a four-time feature winner at Portsmouth, including last year’s $15,000 River Days Rumble. … Four-time track champ R.J. Conley of Wheelersburg, Ohio, won four races at Portsmouth last year, including June’s $5,000 Charlie Swartz Memorial. … Sport mods are on the undercard. … Pits open at 2 p.m. and grandstands open at 4, with hot laps at 6:30. … Watch live on FloRacing.

Who to watch: Ricky Thornton Jr. of Chandler, Ariz., seeks his second straight River Days Rumble triumph at Portsmouth.

Points chase: Before Portsmouth: 1. Ricky Thornton Jr. (5,635); 2. Jonathan Davenport (5,410); 3. Devin Moran (5,395); 4. Hudson O'Neal (4,905); 5. Tim McCreadie (4,890); 6. Garrett Alberson (4,715); 7. Daulton Wilson (4,605); 8. Mike Marlar (4,565); 9. Jimmy Owens (4,345); 10. Max Blair (4,300).

Expected entrants: Among drivers expected to join the top 10 in series standings: Carson Ferguson, Drake Troutman, R.J. Conley, Seth Daniels, Rod Conley, Ross Robinson, Clay Harris, Boom Briggs, Tim Dohm, Brenden Smith, Todd Brennan, Casey Noonan, Kirk Phillips, Shane Bailey, Audie Swartz, Rob Anderzack, Justin Cooper, Josh Bocook, Cory Lawler and others.

Next series race: September 1, Tyler County Speedway (Middlebourne, WV) $30,000