Separate issues for each of the Team Penske Acura DPis have given the Action Express Racing squad a comfortable four lap cushion at the Daytona 24 Hours with eight hours remaining.
The #6 Acura was sent behind the wall during the 14th hour for extensive repairs after picking up an alternator issue, while the sister #7 machine lost ground in hour 16 when Helio Castroneves pitted after sustaining incident damage.
Castroneves made contact with the #31 Action Express Cadillac of Felipe Nasr while battling for second position.
Those eipodes enabled Joao Barbosa to gain a big advantage in the #5 Action Express Cadillac DPi, which now leads by a lap from Nasr.
Barbosa, and team-mates Christian Fittipaldi and Filipe Albuquerque, have been in the top three for much of the IMSA Sportscar Championship season opener, while the #31 cycled into the lead during the 12th hour after recovering from an early drive-through penalty.
Bruno Senna sat third on 16 hours in the #32 United Autosports Ligier, although the World Endurance LMP2 champion was a distant four laps off the pace.
Fourth was Loic Duval in the improving CORE Autosport ORECA LMP2, ahead of Renger van der Zande in the Wayne Taylor Racing Cadillac DPi which is recovering from a major radiator leak that put it seven laps down.
Fernando Alonso's United Autosports Ligier that the Spaniard shares with Lando Norris and Phil Hanson was down in18th overall and working back through the GTLM field following a mechanical problem.
Ford continued to dominate the GTLM category, with Sebastien Bourdais maintaining the #66 car's long-time command at the head of the class field since the halfway point.
Richard Westbrook ended the 16th hour close behind in the #67 machine, which has cycled ahead of its sister entry on a couple of occasions.
The nearest challenger has been the #3 Corvette C7.R of Antonio Garcia, who entered the final eight hours with a lap to make up to the Ganassi Racing duo.
GT Daytona has remained close, with Andrea Caldarelli moving the Paul Miller Racing Lamborghini Huracan into the lead in front of Alvaro Parente in the best of the Michael Shank-entered Acura NSX-GT3s.
