Maverick Vinales saved his best until last as he set the pace in first practice at Aragon with the final lap of the session. The 16 year old saw his title hopes virtually disappear in Misano when he finished down in seventh but clearly looks to be on the pace this time.
For just the third time this year, Vinales will have experience to draw upon having raced here in the Spanish 125cc Championship last year, and he didn't take long getting up to speed, leading the session early on.
Championship leader Nicolas Terol took up his customary position at the top of the FP1 timesheets with a minute to go but Vinales answered with a 2:00.897, a quarter of a second quicker than his fellow countryman had managed.
The Spanish domination was broken by Danny Kent as the Briton finished a sensational third for Red Bull Ajo Motorsport. The 17 year old raced, and beat Vinales two weeks ago to take sixth and looks on course for another promising weekend.
The two Avant-AirAsia-Ajo Derbis followed in fourth and fifth after both had earlier took turns at the top. Johann Zarco's 2:01.622 was good enough to top the timesheets two minutes from time but the late improvements dropped him down the order, with teammate Efren Vazquez pipping him to fourth.
Alberto Moncayo showed promising pace early on before dropping back to sixth while Sandro Cortese took seventh ahead of Miguel Oliveira, another rookie with past experience at the Motorland Aragon circuit.
Hector Faubel finished ninth on the second Aspar Aprilia with Jasper Iwema an impressive tenth for Ongetta-Abbink Metaal.
But it was Vinales who led the pack, and the Blusens rider will have a new teammate for the rest of the season as 17 year old Josep Rodriguez has been brought in to replace Sergio Gadea. The elder Spaniard will still be competing this weekend though as he substitutes for Carmelo Morales in the Desguaces La Torre G22 squad in Moto2.
Rodriguez finished FP1 in 16th, two places ahead of Danny Webb on the Mahindra GP125. Harry Stafford was close behind in 19th while Taylor Mackenzie was 27th overall.