The 31-year-old Brazilian lost the lead to Cadillac Racing’s Tom Blomqvist with 72 minutes remaining in the twice-around-the-clock endurance classic, but a late caution ultimately set up the race-deciding pitstop.
Both drivers short filled, but it was Nasr’s No. 7 Porsche Penske Motorsports 963 that managed to pull ahead off pit lane to reclaim the lead.