Scott Dixon opened the 2012 IndyCar season by setting the fastest time in the first practice session at St Petersburg.
The Chip Ganassi Racing team waited until the hour-long session was half over before sending Dixon and team-mate Dario Franchitti out onto the track, and Dixon set his best time of 1m03.0406s with 11 minutes still on the clock.
Up to that point, Penske driver Ryan Briscoe had been the pace-setter, his best lap of 1m03.5190s ultimately proving 0.4784s shy of Dixon's best, but still good enough to keep the Australian ahead of the rest of the field.
Briscoe's team-mate Will Power was third quickest ahead of Franchitti, whose session was punctuated with a brief trip down the escape road at Turn 10.
Rookie Simon Pagenaud was fifth in his Schmidt-Hamilton entry with Justin Wilson (who held the top spot early on in his Dale Coyne Dallara-Honda), Marco Andretti (Andretti), Mike Conway (Foyt), Graham Rahal (Ganassi) and Helio Castroneves (Penske) rounding out the top 10.
Sarah Fisher Hartman Racing's Josef Newgarden did not make it onto the track until there were less than 10 minutes left to run, but he still managed to post the 11th-quickest time.
Oriol Servia was the quickest of the Lotus-powered entries in 19th, his Dreyer & Reinbold car finishing up 1.2s off Dixon's benchmark, while F1 veteran Rubens Barrichello started his IndyCar career with the 24th-fastest time.
Ganassi driver Charlie Kimball was at the centre of the only major incident of the morning when he ran wide at the exit of Turn 10 and hit the tyre wall. The American was unharmed, and with just a few seconds left before the chequered flag, the accident had no significant impact upon the session.
Pos Driver Team/Car/Engine Time Gap 1. Scott Dixon Ganassi DW12-Honda 1m03.0406s 2. Ryan Briscoe Penske DW12-Chevrolet 1m03.5190s + 0.4784s 3. Will Power Penske DW12-Chevrolet 1m03.5747s + 0.5341s 4. Dario Franchitti Ganassi DW12-Honda 1m03.6013s + 0.5607s 5. Simon Pagenaud Schmidt DW12-Honda 1m03.6417s + 0.6011s 6. Justin Wilson Coyne DW12-Honda 1m03.6704s + 0.6298s 7. Marco Andretti Andretti DW12-Chevrolet 1m03.7928s + 0.7522s 8. Mike Conway Foyt DW12-Honda 1m03.8333s + 0.7927s 9. Graham Rahal Ganassi DW12-Honda 1m03.8522s + 0.8116s 10. Helio Castroneves Penske DW12-Chevrolet 1m03.8728s + 0.8322s 11. Josef Newgarden Fisher DW12-Honda 1m03.8772s + 0.8366s 12. EJ Viso KV DW12-Chevrolet 1m03.9142s + 0.8736s 13. James Jakes Coyne DW12-Honda 1m03.9634s + 0.9228s 14. JR Hildebrand Panther DW12-Chevrolet 1m04.0914s + 1.0508s 15. Takuma Sato Rahal DW12-Honda 1m04.1072s + 1.0666s 16. James Hinchcliffe Andretti DW12-Chevrolet 1m04.1079s + 1.0673s 17. Ryan Hunter-Reay Andretti DW12-Chevrolet 1m04.1239s + 1.0833s 18. Tony Kanaan KV DW12-Chevrolet 1m04.1404s + 1.0998s 19. Oriol Servia Dreyer Reinbold DW12-Lotus 1m04.2946s + 1.2540s 20. Alex Tagliani BHA DW12-Lotus 1m04.3861s + 1.3455s 21. Sebastien Bourdais Dragon DW12-Lotus 1m04.4874s + 1.4468s 22. Charlie Kimball Ganassi DW12-Honda 1m04.6632s + 1.6226s 23. Simona de Silvestro HVM DW12-Lotus 1m04.9147s + 1.8741s 24. Rubens Barrichello KV DW12-Chevrolet 1m05.6681s + 2.6275s 25. Ed Carpenter Carpenter DW12-Chevrolet 1m06.0310s + 2.9904s 26. Katherine Legge Dragon DW12-Lotus 1m07.3331s + 4.2925s