Lorenzo on top in Valencia test

Cal Crutchlow was sixth fastest on his first day as a works Ducati rider, finishing just over one tenth of a second down on new team-mate Andrea Dovizioso.

This year's Moto2 champion Pol Espargaro made his first appearance for the Tech 3 Yamaha squad, ending the day 10th overall.

His 2013 rival Scott Redding meanwhile gave Honda's new prototype bike its first official run-out in what was also his first test with new outfit Gresini. The Briton was 11th fastest.

Honda's newly-crowned champion Marc Marquez and his team-mate Dani Pedrosa opted to sit out the first day of the test, although both are expected to run tomorrow.

Valentino Rossi, now working under new crew chief Silvano Galbusera, finished second overall and just 0.093s shy of Lorenzo's benchmark 1m31.257s, which came in the final hour of the day.

Both Lorenzo and Rossi set their fastest times on a 2013-spec bike, although Rossi also trialled the 2014 development machine Yamaha has brought for both men to sample.

Stefan Bradl put Honda's satellite LCR squad third overall, ahead of a Ducati quintet headed by Andrea Iannone - running with the satellite Pramac squad - Dovizioso and Crutchlow.

The Briton has taken Italian crew chief Daniele Romagnoli across with him following his move from Tech 3. The pair were working alongside Ducati Corse's new general manager Gigi Dall'Igna.

Official test rider Michelle Pirro was next up, with Yonny Hernandez - who will retain his Pramac ride full-time for the 2014 season - eighth.

Hiroshi Aoyama, who also had a 2014 ride with Aspar confirmed in the last two days, rounded out the top nine for his new team.

The team only had one of its new Hondas ready for the first day of testing, meaning 2006 world champion Nicky Hayden did not participate. He is expected to join tomorrow.

Bradley Smith and Randy de Puniet are also set to join the test tomorrow, for the Tech 3 and Paul Bird outfits respectively.

2008 125cc champion Mike di Meglio, who has not ridden since suffering a serious injury in a Moto2 crash at Brno in August, made a surprise outing for Avintia, finishing 14th.