Valentino Rossi will start Sunday's Dutch MotoGP round from fourth on the grid after being pleasantly surprised by the performance of the new Yamaha chassis in the wet Saturday weather.

Sixth in the dry conditions while using the new frame on Friday, the Italian rose to second in the soaking Saturday morning practice. It was the first time Rossi had tried the new frame in such conditions and he went on to hold provisional pole early in the 15-minute Q2 shootout.

But a drying track saw Johann Zarco (Tech 3 Yamaha), Danilo Petrucci (Pramac Ducati) and Marc Marquez (Repsol Honda) all move ahead of The Doctor, leaving Rossi to start from the head of the second row.

"It was a positive day for us because I was very, very curious to try the new chassis in the wet, because also in the wet with the 2017 bike I suffer a lot," began Rossi, speaking in the Assen paddock on Saturday evening. "And the feeling is not so bad because I was competitive from this morning.

"This morning with more water on the track was maybe better than this afternoon. This morning I was second and it's a shame to lose the front row in qualifying, but it's very important to start in the top five. I'm fourth, so I'm in a quite good position and I feel good. This is very important."

Nevertheless, Rossi made clear improvements are needed in both types of conditions ahead of the race.

"Now we have to wait to see the conditions tomorrow," Rossi said. "We have some work to do on the wet - because in the last laps, the top three were stronger than me - and a lot of work still in the dry, because we have some modifications on the bike that we could not try today.

"So I hope for a dry warm-up, for try to understand. And try to improve the pace because yesterday I was not so bad, but it was not enough to fight for the podium.

"Then I hope for full dry, or full wet, to have a real race from the beginning to the end."

Rossi will start Sunday's race fifth in the world championship and 28-points from team-mate Maverick Vinales, but the young Spaniard could only qualify eleventh in the wet.

"For the championship, I think that today is another 'mix'. Because Maverick, who is at the top, is just eleventh. But with a great pace, especially in the dry. Pedrosa, that is in front of me in the championship, is just twelfth," Rossi said. "But on the other side, Zarco who is only behind me by a little bit of points is on pole position and have also a great pace in the dry. So will be interesting."

Rossi on Lowes engine failure: 'For a moment I felt like Cole Trickle in Days of Thunder!' @ValeYellow46 #DutchGP #MotoGP pic.twitter.com/lLZoMycTr3-- CRASH.NET MotoGP (@crash_motogp) June 24, 2017

Rossi received a scare in qualifying when the Aprilia engine of Sam Lowes dramatically exploded just in front of him.

"For a moment I felt like Cole Trickle in 'Days of Thunder'!" quipped Rossi, referring to a scene in the Tom Cruise NASCAR film where Trickle drives into a cloud of smoke (see below). "Because I see the big white smoke and I was completely blind! It was scary, but only for one second and after no problem."