Championship leader Marco Bezzecchi headed Prustel GP team-mate Jakub Kornfeil on the opening day of Moto3 practice for the Catalan Grand Prix.
The KTM Moto2-bound Jorge Martin set the pace in the opening 40-minute lightweight class session of the weekend in Barcelona, with the Gresini rider going top initially with a 1:50.430s.
Martin improved that over the session to a 1:49.290s, and fired in a 1:49.241s at the end to cement top spot by just under three tenths of a second to Sky VR46 rider Nicolo Bulega.
Kornfeil completed the top three on his Prustel GP KTM, with Estrella Galicia 0,0 Honda's Aron Canet and Nieto Team wildcard Raul Fernandez completing the top five.
FP1 pacesetter Martin once again seized control of the timesheets early in FP2 with a 1:50.653s, though was quickly usurped by Niccolo Antonelli, who guided his SIC58 Honda to a 1:49.060s.
Bulega carried on his resurgent form from the opening session into the afternoon, and was only 0.024 seconds adrift of compatriot Antonelli's time 10 minutes into FP2.
Martin's FP1 best still stood as the overall best of the day until the closing minutes of the second session, when Kornfeil upped the pace to a 1:49.060s.
Kornfeil was denied top honours on Friday, though, as team-mate Bezzecchi – who crashed in FP1 – ahead by 0.055s with his final effort of 1:49.005s.
Philipp Oettl completed the top three on his Schedl GP KTM, with Antonelli a few hundredths back in fourth.
Martin ended up fifth overall with a 1:49.222s, with Jaume Masia the last of the field able to beat Martin's FP1 best by setting an identical 1:49.241s on his Besta Capital machine.
Darryn Binder enjoyed a strong morning on his Red Bull Ajo KTM in seventh, with John McPhee on the CIP bike, Bulega and Canet completing the top 10.
As well as Bezzecchi, McPhee took a trip into the Catalunya gravel trap in FP1, as did Kaito Toba and Lorenzo Dalla Porta, while Tatsuk Suzuki suffered a brace of falls across both sessions. Nakarin Atiratphuvapat also crashed in FP2.