Lewis Hamilton's performance in his maiden test outing on a MotoGP bike was "brilliant" according to nine-time world champion Valentino Rossi following their ride swap in Valencia on Monday.

Six-time Formula 1 world champion Hamilton linked up with Rossi through mutual sponsor Monster to sample a MotoGP bike for the first time at the Circuit Ricardo Tormo on Monday, jumping on the 2019-spec Yamaha MotoGP YZR-M1 bike.

It added to Hamilton's growing experience on two wheels, having completed a test on a Yamaha Superbike at Jerez in December 2018 - only this time around, he had Rossi alongside him on-track through the test.

“It was so cool to be out on track and see Valentino ahead of me on the same bike," said Hamilton, who won high praise from The Doctor.

"Technically, Valencia is a hard track and today was windy so at one point I thought it would be difficult for Lewis to continue," said Rossi.

"But he was brilliant on the bike and his position on the M1 was great. I think he had loads of fun which is the main thing."

Hamilton was also on hand to see Rossi complete his first F1 test in almost a decade, as the Italian drove the 2017 F1 championship-winning Mercedes W08 car.

“It’s so awesome to see a legend like Valentino in the car. I’m excited for him, for discovering the car for the first time - it reminds me of my first time in a F1 car," Hamilton said.

"When you see all the team around you, it’s just a different animal.”