Following Sunday's Valencia MotoGP season finale, an official test session is being held at the circuit from Monday to Wednesday.
The test marked Cal Crutchlow's Ducati debut and Moto2 world champion Pol Espargaro's first ride with Monster Yamaha Tech 3.
Espargaro's injured title rival Scott Redding - who previously rode some MotoGP test laps for Ducati - was making his official premier-class debut with Gresini and the new 'Open' class Honda Production Racer.
The RCV1000R was also on track in the hands of Aspar's Hiroshi Aoyama - team-mate and former Ducati star Nicky Hayden will wait until Tuesday due to limited machine numbers.
Likewise the new Forward Yamaha - to be ridden by Aleix Espargaro and Colin Edwards - was not ready in time for Monday.
Also absent was newly crowned world champion Marc Marquez, who like Repsol Honda team-mate Dani Pedrosa took a well-deserved day off.
But there was no rest at the Factory Yamaha team where both Jorge Lorenzo and Valentino Rossi were on track, using the present M1 alongside the 2014 prototype.
Lorenzo, who missed out on the 2013 crown by just four points, lapped comfortably under Pedrosa's new official race lap record to lead day one of the test. Lorenzo and Rossi set their best lap times in the closing minutes.
Rossi was working with his new crew chief Silvano Galbusera for the first time, while former Aprilia Racing boss Gigi Dall'Igna was present in his new role as general manager of Ducati Corse.
The 2014 rules will see the Factory class bikes lose a further litre of race fuel relative to the Open class machines, raising the difference to four litres. The Open bikes must run the full control ECU system, while the Factory entries can use their own software.
Monday's test took place from 12-5pm, with a full day of testing available on both Tuesday and Wednesday.
for more pictures from the test...
1. Jorge Lorenzo
ESP Yamaha Factory Racing (YZR-M1) 1m 31.257s
2. Valentino Rossi
ITA Yamaha Factory Racing (YZR-M1) 1m 31.350s
3. Stefan Bradl
GER LCR Honda MotoGP (RC213V) 1m 31.751s
4. Andrea Iannone
ITA Energy T.I. Pramac Racing (GP13) 1m 31.925s
5. Andrea Dovizioso
ITA Ducati Team (GP13) 1m 31.943s
6. Cal Crutchlow
GBR Ducati Team (GP13) 1m 32.054s
7. Michele Pirro
ITA Ducati Test Team (GP13) 1m 32.698s
8. Yonny Hernandez
COL Ignite Pramac Racing (GP13) 1m 32.745s
9. Hiroshi Aoyama
JPN Power Electronics Aspar (RCV1000R) 1m 33.020s
10. Pol Espargaro
ESP Monster Yamaha Tech 3 (YZR-M1) 1m 33.187s
11. Scott Redding
GBR Go&Fun Honda Gresini (RCV1000R) 1m 34.195s
12. Michael Laverty
GBR Paul Bird Motorsport (PBM-ART CRT) 1m 34.378s
13. Martin Bauer
AUT Remus Racing Team (S&B Suter-BMW CRT) 1m 35.115s
14. Mike Di Meglio
FRA Avintia Racing (FTR-Kawasaki) 1m 36.304s
Official Valencia MotoGP records:
ESP Honda 1m 30.237s
Fastest race lap:
ESP Honda1m 31.628s
Fastest 2013 race laps by manufacturer:
ESP Honda1m 31.628s
ESP Yamaha 1m 31.701s
USA Ducati 1m 32.764s
ESP ART 1m 33.323s
ESP FTR-Kawasaki 1m 33.551s
ITA Suter-BMW 1m 34.153s
AUS FTR-Honda 1m 34.815s
GBR PBM-ART 1m 35.886s