Andre Lotterer, Nick Tandy and Neel Jani calmly controlled their monumental lead on Sunday morning, lapping at a conservative pace in the 919 Hybrid.

But just after 11am local time, Lotterer slowed with a loss of oil pressure just after the start/finish straight, and was forced to try and limp back to the pits on electric power only.

The #1 Porsche had been leading by 13 laps over the #38 DC Racing Oreca LMP2 at that point, a lead of roughly 40 minutes.

Behind, the #2 Porsche moved up to fifth overall with Earl Bamber and then Brendon Hartley at the wheel, 17 laps behind their teammates.

The only remaining Toyota, the #8 TS050 Hybrid of Kazuki Nakajima, is another nine laps behind in 12th place overall.

LMP2: DC Racing still in control

The #38 Jackie Chan DC Racing Oreca kept strengthening its grip on the LMP2 class and second place overall with Thomas Laurent behind the wheel.

The promising Frenchman handed over the controls of the 'Mighty 38' to ex-Audi man Oliver Jarvis, who holds a lap's lead over Mathias Beche in the #13 Rebellion Oreca.

The #13 car is the only Rebellion left challenging for LMP2 and overall podium honours after the #31 car went into the garage for lengthy gearbox repairs.

While the #31 was still being worked on, the #13 Oreca also hit trouble. During a scheduled driver change from Heinemeier Hansson to Beche, the Rebellion crew took off the engine cover to work on the rear end of the car.

Rebellion’s issues moved the #35 Signatech Alpine up into third, just one minute behind the #13 car. The #37 DC Racing Oreca is fourth with Tristan Gommendy taking over from David Cheng.

The #32 United Autosports Ligier is the first non-Oreca LMP2 in fifth, the US-based team surviving a scare when Will Owen suffered a spin through Virage du Pont.

GTE: Thrilling multi-marque battle continues

The GTE Pro battle remains a closely fought affair. The #97 Aston Martin, the #63 Corvette and the #91 Porsche have been trading the lead, position changes dictated by their different pitstop strategies.

At 11am, Corvette driver Antonio Garcia held a 40-second lead - but due an imminent stop - over Patrick Pilet's Porsche with Darren Turner’s Aston with another 20 seconds back in third.

Pilet took over the #91 car from Richard Lietz, who had a fraught moment going wide through the left-hander at Indianapolis.

The #67 Ford GT is also within striking distance in fourth with Andy Priaulx at the controls. With Davide Rigon's #71 AF Corse Ferrari recovering from mechanical issues, the five different GTE Pro manufacturers are currently all represented in the top five.

The #84 JMW Ferrari keeps on dominating the GTE Am class with a three-minute lead over the #55 Spirit of Race and the #62 Scuderia Corsa cars.