Aleix Espargaro and Pol Espargaro win Assen practice sessions

The pair both starred in Assen, winning a session each to give them confidence ahead of Friday's qualifying.

Older brother Aleix, who rides for NGM Forward Racing, won the second run after setting a best lap time of one minute 33.653 seconds.

He left it until the last minute of the session to set the time, as he set a lap record, eclipsing Casey Stoner's efforts in 2012.

And that was enough to ensure he finished ahead of world championship leader Marc Marquez (+0.211secs).

The Repsol Honda rider has won all seven races of the 2014 season and is hoping to break his Assen duck at the race.

Marquez's team-mate, Dani Pedrosa (+0.416secs) was third, while Movistar Yamaha's Jorge Lorenzo (+0.495secs) and Pramac Racing's Andrea Iannone (+0.624secs) rounded out the top five.

In the first practice session, it was Pol Espargaro's chance to shine, with the Monster Yamaha Tech 3 man clocking a time of one minute 34.530 seconds.

Aleix Espargaro (+0.189secs) and Lorenzo (+0.206secs) were second and third respectively.

The practice action continues on Friday with two more runs, before two qualifying sessions.