Factory Ducati team-mates Andrea Dovizioso and Nicky Hayden struggled to find a good set-up during day one of the Czech Republic MotoGP.

Both complained of a lack of grip on the fast, flowing Brno circuit, ending the day ninth (Dovizioso) and tenth (Hayden).

"The afternoon session was very strange, because we suffered a big loss of grip," said Dovizioso, whose best lap time was 1.2s from the top in both sessions.

"Honestly, I thought there was something wrong with my bike because I didn't expect such a big difference compared to this morning.

"We tried a number of things in an effort to understand if there was some problem, so we weren't able to follow the planned work program for the session. Unfortunately, when the temperature rises, it affects us Ducati riders more than the others, and it becomes much more difficult to ride the bike well."

Hayden was a tenth of a second slower, and also in search of a Saturday breakthrough.

"It wasn't a very positive day. This morning we weren't so far off, but in the afternoon I struggled with a lack of grip, problems turning, and chatter. I also made some mistakes with my riding and was running wide. Now we need to understand exactly where to go with the bike's setup and try to do a much better job tomorrow."