The number one Audi driven by Tom Kristensen, Lucas di Grassi and Marc Gene grabbed the lead at the Le Mans 24-hours race, inheriting top spot when its sister car was called into the garage with turbocharger issues.
The second Audi was more than two laps ahead when Marcel Fassler pitted shortly before the 16-hour mark with problems that eventually necessitated changing the turbo.
The 23 minutes they lost saw them drop to third, behind the Porsche driven by former Red Bull Formula One driver Mark Webber.
Di Grassi took full advantage and pulled away despite Webber being on fresher tires, before handing over to Gene, who stretched his lead over the Australian during a brief caution period when both cars were behind different safety cars.
The Porsche had made the early running in the race, setting the pace ahead of the leading Toyota that had Frenchman Stephane Sarrazin at the wheel as intermittent showers caused a spate of minor accidents during the first four hours of action.
Denmark's Kristensen is on course for a record-extending 10th victory in the race at the Sarthe circuit in western France with a little less than seven hours remaining.
(Reporting by Amlan Chakraborty; Editing by John O'Brien)