Former Formula 1 driver Felipe Nasr set the pace in the mock qualifying session held during the pre-Daytona 24 Hours 'Roar' test, with Fernando Alonso 12th quickest.
The session has no impact on the grid for the 24 Hours, which takes place on January 27-28, but it does dictate the allocation of pit boxes and garages.
Nasr led a Cadillac DPi sweep of the top four positions in the #31 Action Express entry, securing top spot with a lap of 1m35.806s posted in the final seconds of the session.
This was the first sub-1m36s lap of the test, and put him 0.231 seconds clear of Tristan Vautier in the #90 Spirit of Daytona Cadillac.
Filipe Albuquerque, in the #5 Action Express car, was third fastest ahead of Renger van der Zande in the #10 Wayne Taylor Racing Cadillac, the latter 0.675s off the pace.
The two Penske Acuras were best of the rest in fifth and sixth places, with Dane Cameron ahead of Ricky Taylor.
Pipo Derani was the best of the Nissan DPis in seventh place, 1.439s down and ahead of the lead Mazda Team Joest entry of Harry Tincknell.
The fastest of the ORECAs was Alex Brundle in ninth place, just ahead of the Miller Motorsports entry of Simon Trummer - with 1.517s covering the top 10.
Alonso was 12th fastest of the 20 prototypes in the United Autosports Ligier JSP217 with a lap of 1m37.515s - the quickest set by that car so far this weekend.
Ganassi Ford on top in GTLM
Chip Ganassi Racing Ford GT driver Joey Hand set the pace in GTLM, securing top spot with five minutes to go with a lap of 1m43.610s.
That relegated team-mate Ryan Briscoe to second, although Oliver Gavin subsequently split the two Fords in the #4 Chevrolet Corvette C7.R with a time just 0.030s slower than Hand.
Briscoe did subsequently improve his time to a 1m43.766s, but it was not enough to get back ahead of Gavin.
In the final minute, Earl Bamber put the #912 Porsche fourth, 0.278s down, and ahead of the second Corvette of Antonio Garcia.
Alessandro Pier Guidi was sixth in the Risi Competizione Ferrari 488 GTE, with the two new BMW M8s of Alexander Sims and John Edwards seventh and eighth.
Mirko Bortolotti was fastest in GTD qualifying, setting his best time of 1m47.374s with four minutes of the session remaining.
The #11 Grasser Lamborghini Huracan driver came close to improving on that, setting a better pace in the first and second sectors of his next quick lap but ending up two hundredths slower.
His earlier lap was quick enough to push Andy Lally in the Magnus Racing Audi R8 LMS to second place by 0.062s.