Marc Marquez wins sprint to extend lead in title race
The 32-year-old Ducati rider extended his lead in the overall standings over his younger brother Alex (Ducati-Gresini), who finished second.
Marc leads Alex by 27 points.
Marc Marquez, who has won the Aragon MotoGP six times in 10 appearances, was headed by his brother at the first corner but passed him at the halfway stage and eased home.
"I had a problem at the start," explained Marc Marquez.
"My plan had been to lead from the start and open up a big lead but for the first three laps I really had to push to get back at Alex.
"When I did get ahead I had to take care of my rear tyre.
"In the end everything went perfectly today."
Rookie Fermin Aldeguer of Ducati-Gresini finished third to make it an all-Spanish podium.
Both Marquez brothers will start on the front row of the grid in Sunday's MotoGP -- the eighth of 22 Grand Prix -- Marc having taken pole earlier on Saturday.
Italy's Franco Morbidelli (Ducati-VR46), who finished fourth in the sprint, fills the front row places.
Morbidelli's compatriot two-time world champion Francesco Bagnaia was the big loser, starting from fourth spot Marc Marquez's team-mate could only finish 12th, and is 84 points adrift of the Spaniard in the standings.
Marquez is seeking to end a three-race losing run, having got off to a blistering start with three wins in the first four MotoGPs.