SEBRING, Fla. – The 68th Mobil 1 Twelve Hours of Sebring presented by Advance Auto Parts featured plenty of twists and turns through its first four hours Saturday at Sebring Int’l Raceway.

At the four-hour mark, Ryan Briscoe was the overall and Daytona Prototype international leader in the No. 10 Konica Minolta Cadillac DPi V.R.

Other class leaders at the four-hour mark were: Scott Huffaker (No. 52 PR1 Mathiasen Motorsports ORECA LMP2 07) in Le Mans Prototype 2 (LMP2), Fred Makowiecki (No. 911 Porsche GT Team Porsche 911 RSR-19) in GT Le Mans (GTLM) and Alessandro Balzan (No. 63 Scuderia Corsa Ferrari 488 GT3) in GT Daytona (GTD).

Saturday’s race is the season finale for the IMSA WeatherTech SportsCar Championship.

The race complexion changed quickly early on. Just 42 minutes in, Ricky Taylor pulled the pole-sitting and championship-leading No. 7 Acura Team Penske Acura ARX-05 DPi into the pits and then behind the wall for lengthy repairs to the left-side intercooler.

Co-driver Helio Castroneves even helped shuffle parts to mechanics in an effort to speed up the process. Taylor rejoined about a half-hour later, 11 laps behind the leader.

“We’re going to fight until the end,” Castroneves said while the work was underway. “Anything is possible. We’re going to keep fighting. We’re going to come back and keep going. … It wasn’t meant to be, but it ain’t over. I don’t want to lose hope right now. I know it sounds difficult. It is.”

Taylor and Castroneves lead No. 10 drivers Renger van der Zande and Briscoe by two points for the DPi championship going into the race.

A penalty at the start of the race cost van der Zande and the No. 10 important track position, when he was issued a drive-through penalty for changing his race line before reaching the flag stand as the green flag waved.

The punishment dropped the No. 10 from second to eighth place in the race, some 30 seconds behind Taylor in the leading No. 7.

A fortuitous full-course caution just after the No. 10 made a green-flag pit stop put Briscoe and the No. 10 into the overall lead with nine hours, 30 minutes remaining.

The No. 52 PR1 Mathiasen Motorsports ORECA LMP2 07, which had clinched the LMP2 driver and team championships before the race, controlled the early action in its class.

The team was focused on securing the IMSA Michelin Endurance Cup championship for Simon Trummer.

The No. 51 Inter Europol Competition ORECA was running a solid second in LMP2 until Jakub Smiechowski slid backward into the turn 17 tire barrier with eight hours, 13 minutes remaining.

Each of the three GTLM manufacturers took turns leading the class during the opening hours. First it was BMW with Connor De Phillippi, then Corvette with Antonio Garcia and finally Porsche with Earl Bamber.

The No. 16 Wright Motorsports Porsche 911 GT3R started on pole in GTD and was clearly superior in the early stages, with driver Jan Heylen building a lead of nearly 20 seconds. That changed quickly about 80 minutes in when the No. 16 fell off the pace with Ryan Hardwick at the wheel, sliding to 11th in class.

Steijn Schothorst took the lead in the No. 11 GRT Grasser Racing Team Lamborghini Huracán GT3, followed by the Nos. 12 and 14 AIM Vasser Sullivan Lexus RC F GT3s.

The No. 11 Huracán encountered its own issues when the car stopped along pit lane two and a half hours into the race. After moving behind the wall for repairs, the car returned but was eight laps down in class.

Both AIM Vasser Sullivan Lexuses were caught in the aftermath after the No. 4 Corvette Racing C8.R dropped fluid on the track with just more than nine hours to go.

Oliver Gavin, in his final full-time race for Corvette, nearly lost control of the No. 4 as he entered the 17th and final turn on the 3.74-mile circuit but was able to pull into the pits.

Not as lucky were Townsend Bell in the No. 12 Lexus and Kyle Kirkwood in the No. 14.

Both slid into the turn 17 tire barrier after running through the fluid spilled from the No. 4. Bell was able to pull his car into the paddock for repairs. The No. 14 was placed on a flatbed truck and towed in with the team ultimately retiring from the race.

No. 14 driver Aaron Telitz entered the race eight points out of the GTD lead. The No. 14 car was 10 points behind the No. 86 Meyer Shank Racing with Curb-Agajanian Acura in the team standings.

The four-hour mark also represented the first scoring opportunity at Sebring for the IMSA Michelin Endurance Cup, which offers points at different segments in each of the WeatherTech Championship endurance races.

In the DPi class, the driver, team and manufacturer titles all were clinched.

The No. 10 Konica Minolta Cadillac DPi-V.R and drivers van der Zande and Briscoe claimed the DPi team and driver titles, while Cadillac wrapped up the manufacturer title.

In LMP2, Simon Trummer and the No. 52 PR1 Mathiasen Motorsport ORECA team secured the Michelin Endurance Cup by leading at the four-hour mark.

The GT classes are still open, except the GTD manufacturer Michelin Endurance Cup was sewn up by Lamborghini.

The rest of the GT endurance titles could be secured at the eight-hour mark.

In GTLM, the No. 24 BMW Team RLL M8 GTE and drivers John Edwards and Jesse Krohn have the lead with 41 points, leading the No. 911 Porsche GT Team 911 RSR-19 and co-drivers Nick Tandy and Frederic Makowiecki by five points.

BMW also has a three-point advantage over Porsche, 45-42.

In GTD, the No. 48 Paul Miller Racing Lamborghini Huracán GT3 squad of Bryan Sellers, Madison Snow and Corey Lewis currently have a six-point lead over the No. 63 Scuderia Corsa Ferrari 488 GTE and WeatherTech drivers Cooper MacNeil and Jeff Westphal.

The No. 63 team will need to score the maximum five points in both of the final two segments in order to win the title.