Rossi leads Yamaha charge with Assen pole.

The persistent rain that has showered Assen for the past two days finally lifted this afternoon - providing a thrilling final qualifying session for Saturday's Dutch TT.

Although rain didn't stop until just 15-minutes before the session began, strong winds and Assen's uniquely cambered surface ensured that the track was no more than damp by the start of the hour long qualifier.

As a result, Sete Gibernau's 2min 12.54secs provisional pole time - and the Friday order in general - was almost instantly irrelevant: With lap times stumbling, morning pace setter Kenny Roberts was soon circulating in the 2min 4secs bracket, then exchanging the top spot with Yamaha's Carlos Checa - each knocking almost a second from their previous best with successive laps.

Meanwhile, knocking of a different kind was occurring between Repsol Honda team-mates Alex Barros and Nicky Hayden as they approached the final chicane. Hayden was in front, but being caught by Barros, who moved inside on the brakes to overtake the young American... Nicky appeared not to see him, stuck to his line and forced Barros to take avoiding action - which ended with the Brazilian sliding down the road and into the gravel, fortunately without hitting Hayden.

Back on track and with ten-minutes gone the rapid improvements were continuing - and now headed again by Checa, the Spaniard having raised the standard to a 2mins 2.2secs circulation (the dry 2003 pole time set by Loris Capirossi was 1min 59.77secs).

However, Checa would lose the position soon after when team-mate Valentino Rossi hit the top for the first time. In turn, Rossi's reign would also be brief, but this time ended by Gibernau - the championship leader taking to the track for the first time with 15mins gone (by which point he'd dropped to eleventh) and quickly quelling the Yamaha revolt as he lapped 1.358secs faster than the flying Italian.

Nevertheless, by the midway point of the hour Rossi was back in front; the five-times world champion having pitted for new, and almost certainly fully slick tyres, just before the halfway stage - helping him to deliver two fast laps that put Vale 0.254secs clear of his Honda opponent.

Behind the top two by that stage were Checa (third), Xaus, Capirossi, Melandri, Edwards, McWilliams, Roberts, Barros, Biaggi and Hodgson.

The order at the front would remain unchanged until, with a quarter of the session left, Checa returned to the top with a 2min 0.035secs - handing the Fortuna backed rider a slim 0.133secs advantage as the final runs began.

The last five-minutes saw further changes throughout the field, the most significant of which was a new lap record for Checa - but it wouldn't be enough to prevent Rossi taking pole as Italian sliced 0.682secs inside his team-mate's time with the chequered flag being waved.

Gibernau looked most likely to upset the Yamaha top two, but the Telefonica Honda rider's last lap was disappointingly off the pace (+1.1secs) and he would be left third. Sete later explained that his clutch had been slipping throughout his last lap.

There were also mechanical dramas for Kawasaki's Shinya Nakano, when a sizable piece of what looked like some form of bodywork fell from his ZX-RR just after he'd taken a superb fifth (+1.99secs), forcing him to cruise back to the pits.

Despite the early end, Nakano will start an excellent fifth for tomorrow's race, just behind Marco Melandri (+1.96secs) - the Italian completing another strong showing from Yamaha that saw three M1s in the top four.

The next fastest Honda behind Gibernau was that of Barros, the Brazilian veteran recovering from his fall to claim sixth (+2.2secs) on thew grid for his 200th premier-class GP.

Early leader Kenny Roberts will head the third row for Suzuki (+2.4secs), alongside the top Camel Honda of Makoto Tamada (+2.45secs) and class rookie Ruben Xaus (+2.5secs). Xaus was again the top Ducati, no less than five places in front of Troy Bayliss (+2.9secs), with Loris Capirossi a distant fifteenth (+3.2secs) and Neil Hodgson just twentieth (+4.1secs).

Aprilia riders Shane Byrne and Jeremy McWilliams featured well in the early stages, but as the rain disappeared so did their hopes and they will start 18th and 19th respectively.

WCM's Michel Fabrizio was also unable to replicate his wet weather heroics, but will still start in front of both Proton KRs and his team-mate Chris Burns tomorrow.

Full times to follow...

Final qualifying:

1. Rossi
2. Checa
3. Gibernau
4. Melandri
5. Nakano
6. Barros
7. Kenny Roberts
8. Tamada
9. Xaus
10. Hopkins
11. Hofmann
12. Biaggi
13. Edwards
14. Bayliss
15. Capirossi
16. Hayden
17. Abe
18. Byrne
19. McWilliams
20. Hodgson
21. Fabrizio
22. Aoki
23. Kurtis Roberts
24. Burns