Jorge Martin demolished the Aragon Moto3 record to take his ninth pole of the season in qualifying for the Aragon Grand Prix, with Jaume Masia 0.537 seconds adrift.
Points leader Martin set the early pace in qualifying with a 1:58.747s, though the Gresini man was soon pipped by Sky VR46's Nicolo Bulega by a tenth.
Martin regained top spot away from Bulega on his second flying lap with a 1:58.448s, before the sister VR46 KTM of Dennis Foggia demoted the Spaniard by a tenth.
With 10 minutes of the session elapsed, Gabriel Rodrigo guided his RBA machine to a 1:57.937s, dipping a few hundredths underneath Marco Bezzecchi's weekend-best of 1:57.961s set in FP3.
Rodrigo's lap stood as the benchmark through to the final few minutes of the session, when a flurry of fast laps saw the order shaken up repeatedly.
Bezzecchi beat Rodrigo's time first in the final 30 seconds of the session, the Prustel GP rider firing in a 1:57.855s without the benefit of a slipstream.
However, title rival Martin was lighting up the timing screens on his final lap, and obliterated the outright Moto3 lap record by almost seven tenths with a 1:57.066s.
Bester Capital Dubai's Masia equalled his best qualifying result of the year in second, while the Moto2-bound Enea Bastianini completed the top three on his Leopard Honda.
Tony Arbolino was shuffled back to fourth with his laptime of 1:57.774s ahead of Foggia and Bezzecchi, while Niccolo Antonelli guided his SIC58 Honda to seventh.
However, Antonelli will be demoted to 19th on the grid after receiving a 12-place grid penalty for irresponsible riding during FP3.
This will promote Rodrigo, who was eighth in the end having sat atop the timesheets for most of the session. Aron Canet and Fabio Di Giannantonio completed the top 10.
A scary collision left the Team Asia duo of Nakarin Athiratphuvapat and Kaito Toba at the back of the field.
Athiratphuvapat clattered into the rear of his teammate under braking for Turn 3, sending Toba into a highside. The latter's physical condition is not known at present, while the former walked away unscathed.
