A late lap on new soft tyres propelled Valentino Rossi to the top of the timesheets during opening practice for the Catalunya MotoGP.

Riding on the resurfaced Barcelona circuit, which also features a return to the fast penultimate corner for 2018, the Italian set a best time of 1m 39.456s to finish the session 0.347s clear of Ducati's Andrea Dovizioso.

However, Dovizioso set his best lap using a new hard rear tyre. The Italian also narrowly edged out Mugello winning team-mate Jorge Lorenzo, whose best came on the soft-medium rubber combination.

Reigning champion Marc Marquez set the pace for most of the session before being bumped down the order to fourth in the closing stages.

The Repsol Honda star - who leads the standings by 23-points from Rossi despite a second DNF of the season last time at Mugello - posted his best time of the session on his opening run, using soft-medium tyres.

Also using that tyre combination were Johann Zarco (Monster Yamaha Tech3) and Maverick Vinales (Movistar Yamaha), whose fifth and sixth places - combined with Rossi's P1 performance - will have helped ease Yamaha's fears after last year's Barcelona woes.

Vinales had also set the fastest lap time at the recent private Catalunya test, with a 1m 38.974s.

Cal Crutchlow (LCR Honda), Tito Rabat (Avintia Ducati), Andrea Iannone (Suzuki) and Jack Miller (Pramac Ducati) completed the top ten. Iannone and Miller both fell, at the start and end of the session respectively, the Australian while trying to pass Bradley Smith.

Aleix Espargaro was eleventh for Aprilia, ahead of Dani Pedrosa (Repsol Honda) and top rookie Hafizh Syahrin (Monster Yamaha Tech3).

Wild-cards Mika Kallio (KTM) and Sylvain Guintoli (Suzuki) were 15th and 24th respectively, out of the large 26 rider line-up.