Casey Stoner and Honda just got the better of Jorge Lorenzo and Yamaha during the first head-to-head test of 1000cc MotoGP machines, at Brno on Monday.
Stoner, who had previously tested the RC213V for two days at Jerez in mid-May, confirmed his initial positive impression by leading for most of the day - until Lorenzo, making his 1000cc debut, moved ahead in the final two hours.
Stoner - who extended his MotoGP title lead to 32 over Lorenzo with victory on Sunday - then responded on the 54th of his 57 laps, edging just 0.085sec under Lorenzo's best before rain arrived in the final 30 minutes.
"Today was another good shakedown but we still have some work to do, we found a few positive things and confirmed certain directions to take and move forward," said Stoner, pictured dragging his elbow on the RC213V.
"We had a few small problems with chatter but it's something that shouldn't be too difficult to sort out through engine braking and engine management systems, which are areas we can definitely improve in, along with the chassis.
"The engine for me is fantastic, to ride the 1000 with more grunt and more power it's a lot of fun, it has incredible acceleration, most of the time too much!
"We tested a couple of the new tyres and had some issues, the traction didn't feel that great and they seemed to create a lot more chatter so we went back to the standard tyres and the chatter seemingly disappeared.
"From the data we have from the first test and this test, we can go away and come back with the next step and take it from there."
Unlike Stoner, reigning MotoGP champion Lorenzo didn't race during the previous 990cc MotoGP era (2002-2006), but proved he will have little trouble adapting his style to the larger engine capacity.