Andrea Dovizioso made his Yamaha and 1000cc MotoGP debut during this week's Valencia test.
The former Repsol Honda rider, third in this year's championship, finished the test in fifth position for his new Monster Yamaha Tech 3 team.
Dovizioso was 1.4sec behind former team-mate Dani Pedrosa and 0.7sec from new team-mate Cal Crutchlow, in fourth.
“Firstly I want to thank the Tech 3 staff for making me feeling immediately welcome and at home this week. I've been really excited to start this new adventure together and it was a positive and productive test," said Dovizioso.
"This test was my first chance to ride the 1000cc bike and the power of the engine is very impressive. The riding style is very close to 800cc and the bike has a lot of good points for my style.
"There are some areas I have identified we can improve for the next test in Sepang and I gave a lot of important feedback that should help Yamaha improve the bike during the winter break.
"Now I will take a break to recharge the batteries and return in Sepang looking forward to getting back on the bike and carrying on the positive work we did here in Valencia.”