The second pre-season test of the year saw windy conditions, which hampered testing in Valencia, joined by rain as Terol took charge at the Jerez circuit.
The Valencian Aspar riders lap of 1m 53.831 saw his Suter into first place but Simone Corsi was also sharp in the wet, less than two tenths behind aboard the NGM Forward Racing Speed Up machine.
Julian Simon made it three different manufacturers at the front, placing the Italtrans Kalex third, though nearly half a second adrift of the Italians time.
Valencia test pace-setter Pol Espargaro was narrowly behind his fellow countryman Simon and was fourth fastest for the Tuenti HP 40 team.
Session one had been dominated by the Marc VDS Team, with Mika Kallio and Scott Redding swapping top position frequently, Redding eventually finished the day fifth fastest in the overall combined times while Kallio was seventh.
Frenchman Johann Zarco moved things up a notch for the Came IodaRacing Project as conditions improved posting the sixth fastest time for the team on his Suter.
Ricky Cardus made it two Forward Racing machines inside the top ten in eighth, Jordi Torres achieved the same feat for Aspar in ninth. Espargaro’s team mate Tito Rabat completed the top ten fastest riders on day one.
Former Moto2 champion Toni Elias was twelfth quickest for the Italtrans team and while normally associated with being able to master wet conditions Ant West surprised by finishing the day 23rd overall for QMMF. Reigning Moto3 champion Sandro Cortese finished 25th for Dynavolt Intact GP.
British hopefuls Danny Kent (Tech3) and Kyle Smith (Blusens Avintia) continued to find their feet in Moto2 and placed 17th and 19th respectively.
Swiss Interwetten rider Tom Luthi was not present as he recovers from the multiple fractures he suffered in his crash with Ratthapark Wiliarot at the Valencia test. Wiliarot finished the day 21st for Gresini.
Combined Moto2 times (day one):
1. Nico Terol Mapfre Aspar Team Moto2 (Suter) 1m 53.831s
2. Simone Corsi NGM Mobile Racing (Speed Up) 1m 53.999s
3. Julian Simon Italtrans Racing Team (Kalex) 1m 54.468s
4. Pol Espargaro Tuenti HP 40 (Pons Kalex) 1m 54.493s
5. Scott Redding Marc VDS Racing Team (Kalex) 1m 54.571s
6. Johann Zarco Came IodaRacing Project (Suter) 1m 54.833s
7. Mika Kallio Marc VDS Racing Team (Kalex) 1m 54.986s
8. Ricky Cardus NGM Mobile Forward Racing (Speed Up) 1m 54.989s
9. Jordi Torres Mapfre Aspar Team Moto2 (Suter) 1m 55.101s
10. Esteve Rabat Tuenti HP 40 (Pons Kalex) 1m 55.241s
11. Mike Di Meglio JIR Moto2 (MotoBI) 1m 55.285s
12. Toni Elias Blusens Avintia (Kalex) 1m 55.424s
13. Xavier Simeon Maptaq SAG Zelos Team (Kalex) 1m 55.467s
14. Mattia Pasini NGM Mobile Racing (Speed Up) 1m 55.666s
15. Takaaki Nakagami Italtrans Racing Team (Kalex) 1m 55.807s
16. Dominique Aegerter Technomag carXpert (Suter) 1m 55.974s
17. Danny Kent Tech 3 (Tech 3) 1m 56.174s
18. Randy Krummenacher Technomag carXpert (Suter) 1m 56.508s
19. Kyle Smith Blusens Avintia (Kalex) 1m 56.607s
20. Alex De Angelis NGM Mobile Forward Racing (Speed Up) 1m 56.726s
21. Ratthapark Wilairot Honda Gresini Moto2 (Suter) 1m 56.788s
22. Louis Rossi Tech 3 (Tech 3) 1m 56.892s
23. Anthony West QMMF Racing Team (Speed Up) 1m 56.903s
24. Rafid Topan Sucipto QMMF Racing Team (Speed Up) 1m 56.929s
25. Sandro Cortese Dynavolt Intact GP (Kalex) 1m 57.025s
26. Doni Tata Pradita Federal Oil Gresini Moto2 (Suter) 1m 58.308s
27. Yuki Takahashi Idemitsu Honda Team Asia (Moriwaki) 1m 59.115s