Hayden leads the way in Jerez testing

The American set a best lap of 1m39.200 seconds on his 84th lap, which at that stage of proceedings put him one second clear of the opposition.

But although a lot of his rivals managed to close the gap as they tried late-run qualifying laps at the end of the day, nearest challenger Randy de Puniet on the LCR Honda was still left 0.244 seconds adrift.

Hayden admitted the experience of the first day had been a big boost to his confidence.

"I would definitely say this was the best first day of tests we've had so far this year," he said. "And we knew it was important, because the weather experts are saying there's a really good chance of rain the next two days."

Jorge Lorenzo on the Michelin-shod Fiat Yamaha ended the day third quickest, while Tech 3 Yamaha duo Colin Edwards and James Toseland continued to show the progress their team had made in switching to Michelins to end the test fourth and fifth fastest on the timesheets.

Morning pace setter Valentino Rossi could manage no better than eighth on the timesheets, as he ended up behind the Honda Gresini duo of Alex de Angelis and Shinya Nakano - who were the fastest Bridgestone runners.

Rossi was far from downbeat about his final placing in the standings, though.

"For the first day it's not so bad at all, I feel good with the tyres and the balance and power of the engine is also okay," he said. "Of course we're not at 100% and we need to improve in some areas, especially in the entry to the corner where we're not yet at the maximum.

"We tried a new generation of Bridgestone qualifying tyre today, whilst tomorrow we will have the more standard tyre, which we were very fast with in Sepang, so I think we will be able to fight with the others in the 'qualifying' session. Overall we've made a very good start and I feel confident that we can continue to be even faster tomorrow."

Despite slipping down the order late on, Rossi still ended the day ahead of MotoGP champion Casey Stoner, whose ninth fastest time was more than 1.4 seconds behind Hayden.

Hayden's teammate Dani Pedrosa made his return to action for the first time since hurting his hand in a crash at Sepang, but he was only able to complete 37 laps. The Spaniard was seen applying an ice pack to his hand each time he got off the bike

The other returning rider, Kawasaki's John Hopkins, also had a limited outing as he completed just 26 laps as he worked on recovering from the thigh injury he picked up in his crash during Phillip Island testing.

Pos  Rider             Bike          Time              Laps
 1.  Nicky Hayden      Honda    (M)  1:39.200           107
 2.  Randy de Puniet   Honda    (M)  1:39.444  + 0.244   82
 3.  Jorge Lorenzo     Yamaha   (M)  1:39.528  + 0.328   94
 4.  Colin Edwards     Yamaha   (M)  1:39.629  + 0.429   78
 5.  James Toseland    Yamaha   (M)  1:39.678  + 0.478   91
 6.  Alex de Angelis   Honda    (B)  1:40.165  + 0.965   75
 7.  Shinya Nakano     Honda    (B)  1:40.192  + 0.992   82
 8.  Valentino Rossi   Yamaha   (B)  1:40.641  + 1.441   92
 9.  Casey Stoner      Ducati   (B)  1:40.651  + 1.451   66
10.  Andrea Dovizioso  Honda    (M)  1:40.767  + 1.567   58
11.  Loris Capirossi   Suzuki   (B)  1:40.843  + 1.643   64
12.  Daniel Pedrosa    Honda    (M)  1:41.352  + 2.152   37
13.  Marco Melandri    Ducati   (B)  1:41.392  + 2.192   83
14.  Toni Elias        Ducati   (B)  1:41.703  + 2.503   91
15.  Chris Vermeulen   Suzuki   (B)  1:41.763  + 2.563   79
16.  Anthony West      Kawasaki (B)  1:41.821  + 2.621   83
17.  John Hopkins      Kawasaki (B)  1:41.901  + 2.701   26
18.  Olivier Jacque    Kawasaki (B)  1:42.557  + 3.357   67
19.  Niccolo Canepa    Ducati   (B)  1:42.652  + 3.452   61
20.  Sylvain Guintoli  Ducati   (B)  1:42.698  + 3.498   68
21.  V. Guareschi      Ducati   (B)  1:43.435  + 4.235   66