Nasr had the honour of taking the chequered flag – twice, after confusion created by Race Control – in a grandstand finish to the IMSA SportsCar Championship season-opener.
Almost four hours of continuous green flag running gave way to a Caution in the final hour, caused by a plenum fire for the #12 Vasser Sullivan Lexus RC F GT3, which brought cars back into pit lane.
Blomqvist pushed hard, but could not find a way past Nasr, who clinched a first outright win in the 24 Hours of Daytona in 21 years for Porsche and 55 years for Penske by a margin of 2.112s after 791 laps.
The #7 Porsche had taken the lead back from the #31 Cadillac in the 19th hour after a tense battle between Campbell and Jack Aitken.
The two nearly made contact several times before the McElrea Racing alumni finally got the move done on the run to Turn 1, and Nasr was able to keep the lead when he got back behind the wheel.
Nasr was as much as 18 seconds to the good in the closing hours but lost that lead in the penultimate round of pit stops when the race was brought under Caution due to debris.
The #6 Porsche got home in fourth despite multiple hold penalties for powertrain parameter breaches and Kevin Estre's off on cold tyres with less than four hours to go.
The IMSA season continues with the Mobil 1 Twelve Hours of Sebring on March 13-16 (local time).