Porsche remains in control at the halfway mark of the Six Hours of Mexico, with the No. 2 car of Earl Bamber out front.
The Kiwi holds a 18-second lead over the sister, Andre Lotterer-driven No. 1 Porsche 919 Hybrid, in a gap that closed up following a longer-than-usual stop for Bamber to replace a FIA-mandated fuel flow sensor.
The two Porsches had run nose-to-tail for much of the third hour until the No. 1 car was handed a drive-through penalty for Nick Tandy speeding in the pit lane.
The No. 8 Toyota TS050 Hybrid of Kazuki Nakajima runs third but more than 1 minute and 15 seconds behind and essentially out of contention unless the Porsches hit trouble.
LMP2 is led by the No. 31 Vaillante Rebellion Oreca 07 Gibson of Julien Canal, ahead of Roman Rusinov, who had a hard-fought battle with Gustavo Menezes for second.
The American ran off course no fewer than four times over the course of a lap and was forced to surrender the position due to his driving tactics.
Trouble hit the class championship-leading No. 38 Jackie Chan DC Racing Oreca, which made at least two trips to the garage with clutch issues.
The No. 71 AF Corse Ferrari 488 GTE of Sam Bird leads GTE-Pro, with its sister No. 51 entry up to third, despite a left-rear puncture after contact with the No. 66 Ford GT of Olivier Pla, which sent the Ford to the garage.
Matteo Cairoli, meanwhile, leads GTE-Am in the class pole-sitting No. 77 Dempsey Proton Racing Porsche 911 RSR.