Daniel Abt topped the first day of GP3's post-season test at Valencia, eventually ending more than six tenths of a second clear of the rest of the field.
The ART driver was the first man to break the 1m40s barrier in cold early conditions, and then moved comfortably clear of his opposition when he bolted on fresh rubber as the day drew to a close.
Jenzer Motorsport's Patric Niederhauser ended the day second fastest but 0.636s in arrears - with Victor Guerin (ART) and Conor Daly (Carlin) also able to get within seven tenths of Abt's benchmark.
GP3 regular Matias Laine (Manor) was one of the first drivers to switch to slicks in the morning and was also on top for much of the afternoon, although he fell to fifth by the day's end.
Marlon Stockinger completed a strong day for Lotus ART, who won both the drivers' and constructors' titles this season, by finishing sixth fastest ahead of Tio Ellinas (Manor).
MW Arden's Will Stevens and Maxim Zimin, and Status GP's Tom Blomqvist - a 2011 McLaren AUTOSPORT BRDC Award finalist - all had spells at the top of the timesheets but finished the day in eighth through to tenth.
Day One times:
Pos Driver Team Time Gap 1. Daniel Abt ART 1m27.505s 2. Patric Niederhauser Jenzer 1m28.141s + 0.636s 3. Victor Guerin ART 1m28.143s + 0.638s 4. Conor Daly Carlin 1m28.186s + 0.681s 5. Matias Laine Manor 1m28.237s + 0.732s 6. Marlon Stockinger ART 1m28.321s + 0.816s 7. Tio Ellinas Manor 1m28.443s + 0.938s 8. Will Stevens MW Arden 1m28.566s + 1.061s 9. Maxim Zimin MW Arden 1m28.596s + 1.091s 10. Tom Blomqvist Status 1m28.609s + 1.104s 11. Will Buller Carlin 1m28.771s + 1.266s 12. Tamas Pal Kiss Atech CRS 1m28.870s + 1.365s 13. Yuhi Sekiguchi RSC Mucke 1m29.399s + 1.894s 14. Robert Visoiu Jenzer 1m29.651s + 2.146s 15. Fabio Gamberini MW Arden 1m29.743s + 2.238s 16. Facu Regalia Status 1m29.943s + 2.438s 17. Kotaro Sakurai Status 1m30.187s + 2.682s 18. Lorenzo Camplese Tech 1 1m30.368s + 2.863s 19. Pascal Wehrlein RSC Mucke 1m30.442s + 2.937s 20. Michela Cerruti Addax 1m31.083s + 3.578s 21. Dmitry Suranovich Manor 1m31.181s + 3.676s