Marc Marquez completed a clean sweep of this week's Austin MotoGP test as he beat Honda team-mate Dani Pedrosa again on Thursday.
Honda had the track largely for itself for day three in Texas, with Yamaha having elected to stick to a two-day programme.
Marquez made another big improvement to get down to a 2m03.281s while working on set-up adjustments.
That was 0.6 seconds faster than Pedrosa, but the 2012 MotoGP runner-up only completed 24 laps to his team-mate's 60 before stopping due to neck pain.
LCR Honda's Stefan Bradl was 0.9 off Marquez in third.
CRT wildcard Blake Young also stayed on for another day of testing with Attack Performance's chassis.
Pos Rider Team/Bike Time Gap Laps 1. Marc Marquez Honda 2m03.281s 60 2. Dani Pedrosa Honda 2m03.898s + 0.617s 24 3. Stefan Bradl LCR Honda 2m04.225s + 0.944s 43 4. Blake Young Attack APR-Kawasaki 2m12.186s + 8.905s 42