Porsche holds a narrow gap over Audi with drying conditions in the final two hours of the Six Hours of Shanghai.
Timo Bernhard has put his No. 17 Porsche 919 Hybrid into the lead, following a heated battle with Neel Jani and Benoit Treluyer for the top spot.
Treluyer took over the lead with 3 hours and 37 minutes to go, although Jani retook the top sport 20 minutes later, in a frantic battle with LMP1 juggernauts.
The pair of Porsches, still on wet tires, have been struggling for grip in the changing conditions.
Pegasus Racing controls LMP2, with its main rival, the No. 30 Tequila Patron ESM Ligier JS P2 Honda dropping out with gearbox failure after leading in the hands of Ryan Dalziel.
The class championship-leading No. 91 Porsche Team Manthey Porsche 911 RSR of Richard Lietz is out front in GTE-Pro, with the No. 98 Aston Martin Vantage V8 leading GTE-Am heading into the final one-third of the race.