Ducati's Dovizioso is rider to beat at Brno - MotoGP leader Marquez

Dovizioso and Marquez were the only two riders to place in the top 10 in Friday's combined classification without using a fresh soft rear tyre in FP2, finishing the session fifth and 10th respectively.

Marquez suggested that his Ducati rival is a step ahead, although he and his practice-topping Honda team-mate Dani Pedrosa were among his nearest rivals on pace.

"At the moment I think the fastest guy on the track is Dovizioso," Marquez said.

"Then it's Dani, me and two to three more riders with a very similar pace."

Dovizioso was buoyed by his Friday showing, as he admitted he and the Desmosedici GP18 were performing above expectations at a track where Ducati has not scored a podium since 2010.

"It was really good, a bit better than what we expected - our speed is pretty good," he said.

"That is the best you can have the first day because [it] gives you the chance to make more laps on the tyres and you are able to prepare a lot for the race.

"We didn't use the soft tyre at the end like Marc, and we are in the top 10. That is very important and positive.

"We showed real speed with used and with new tyres so [I'm] pretty happy.

"It doesn't mean it will be enough because the consumption on the tyre is the biggest point, so we are working a lot on that."

While Dovizioso is comfortably inside the provisional cut-off for an automatic Q2 spot, Marquez is in by less than a hundredth of a second with the third practice session still to run.

The Spaniard, who has forgone a qualifying simulation run on Friday on a number of weekends this year, said he had been taking cues from Dovizioso.

But Marquez said it was a "risky" approach, and admitted it had played a part in him having to fight through Q1 in Barcelona earlier this year.