Ben Spies has put himself on course for a fourth consecutive World Superbike pole position after claiming the provisional top spot in Qualifying 1 at Assen.

Building on the fastest time he achieved in free practice earlier, the American was in impressive form around the Dutch circuit to emerge as the only rider to slip into the 1min 38secs bracket, three tenths up on his closest competition.

Although Spies spent much of the 45 minute session on the fringes of the top ten, a vast improvement with ten minutes remaining saw him snatch the initiative. He would swiftly go on to knock a further two tenths off with his final attempt to put him in a good position for tomorrow's more pivotal sessions.

Before that, Jakub Smrz had been on course to secure provisional pole position after making a substantial improvement on his earlier effort of 16th fastest in practice.

At one stage six tenths quicker than anyone else on the circuit, the Guandalini Ducati rider was fastest for 15 minutes before being bumped down to second position by Spies.

Joining him on the provisional front row is third place Yukio Kagayama, who also made a big improvement on his practice performance, and fourth place Carlos Checa, the Spaniard running consistently at the front for much of the session.

Michel Fabrizio upheld Ducati Xerox honours in fifth position, but championship leading team-mate Noriyuki Haga, who has been complaining of a cold this weekend, could only manage 12th fastest.

Nonetheless, Regis Laconi helped Smrz and Fabrizio fly the Ducati flag in sixth position, ahead of Max Neukirchner, while Jonathan Rea, Ryuichi Kiyonari and Leon Haslam made it a decent day for the Honda representatives too.

Outside the top ten, Troy Corser ended day one an encouraging 11th on the BMW, ahead of Aprilia's top rider Max Biaggi, who was down in 16th position. Between them, Shane Byrne and Tom Sykes were 13th and 15th quickest, the latter seeing his hopes of a good finish to the day scuppered by a fall on his final lap.

Elsewhere, Tommy Hill sneaked into a provisional Superpole slot in 19th, while Stuart Easton is just five tenths off a spot inside the top twenty himself after making a 1.7secs improvement on his free practice effort. Even so, he remains 25th heading into Q2, just one place behind Kawasaki team-mate Makoto Tamada.