Will Power set the opening pace for this weekend's IndyCar double-header in Houston after posting the fastest time in the delayed first practice session.
The session started almost three hours later than originally scheduled after severe bumps near the exit of the main straight forced the series to construct a temporary chicane before the first corner.
Power's best lap of 1m06.8320s came towards the end of his run and left the Penske driver comfortably clear of his rivals, with next-fastest driver, Ganassi man Scott Dixon, 0.2s down on the Australian's pace.
But the main calling card for the session were the accidents that left two cars needing significant repairs before the second outing later this afternoon.
The first came when Josef Newgarden fell victim to the extremely narrow gap provided by the makeshift chicane and ploughed into the tyre stack on the left side of the track.
Later, reigning series champion Ryan Hunter-Reay was launched skyward after thumping into the kerbing at Turn 2 and landed in the inside wall.
Pos Driver Team/Engine Time Gap 1. Will Power Penske/Chevy 1m06.832s 2. Scott Dixon Ganassi/Honda 1m07.079s +0.247s 3. Helio Castroneves Penske/Chevy 1m07.103s +0.271s 4. Ryan Hunter-Reay Andretti/Chevy 1m07.225s +0.393s 5. Justin Wilson Coyne/Honda 1m07.360s +0.528s 6. James Jakes Rahal/Honda 1m07.745s +0.913s 7. EJ Viso Andretti/Chevy 1m07.752s +0.920s 8. Tony Kanaan KV/Chevy 1m07.804s +0.972s 9. Dario Franchitti Ganassi/Honda 1m07.990s +1.158s 10. Simon Pagenaud Schmidt/Honda 1m08.131s +1.299s 11. Simona de Silvestro KV/Chevrolet 1m08.242s +1.410s 12. Graham Rahal Rahal/Honda 1m08.255s +1.423s 13. James Hinchcliffe Andretti/Chevy 1m08.258s +1.426s 14. Tristan Vautier Schmidt/Honda 1m08.451s +1.619s 15. Josef Newgarden Fischer/Honda 1m08.699s +1.867s 16. Takuma Sato Foyt/Honda 1m08.734s +1.902s 17. Oriol Servia Panther/Chevy 1m08.852s +2.020s 18. Marco Andretti Andretti/Chevy 1m08.886s +2.054s 19. Mike Conway Coyne/Honda 1m08.942s +2.110s 20. Luca Filippi Herta/Honda 1m09.048s +2.216s 21. Sebastian Saavedra Dragon/Chevy 1m09.078s +2.246s 22. Charlie Kimball Ganassi/Honda 1m09.784s +2.952s 23. Ed Carpenter Carpenter/Chevy 1m09.891s +3.059s 24. Sebastian Bourdais Dragon/Chevy 1m14.198s +7.366s All drivers use Dallara DW12 chassis