The World Superbike Championship will return to Imola, scene of its greatest title showdown, for the first time since 2006 this weekend.

The 2002 Imola season finale (pictured) produced a breathtaking title showdown between world champions Colin Edwards and Troy Bayliss, which ended in the American's favour, although Bayliss went on to clinch his second crown at the Italian circuit in 2006.

WSBK returns for round twelve of the 2009 championship to find the circuit slightly modified in the section from the Rivazza to the pit straight, following the construction of a new chicane.

Eleven WSBK races have been held at Imola, and the list of winners includes Ruben Xaus and Regis Laconi, with three victories apiece, Edwards (two) and one each for Chris Vermeulen, Alex Barros and Troy Bayliss.

As for the manufacturers, Ducati lead the way with six wins, followed by Honda with four and Aprilia with one.

But Yamaha has an excellent chance of adding its name to that list, with rookie superstar Ben Spies arriving at Imola with 12 wins from the 22 races so far this season - and having finally taken the title lead from Noriyuki Haga by 18 points at the last race in Germany.

Haga, who finished first or second in the first nine races of the season, has now gone ten races without a victory - partly due to injuries sustained at Donington Park - and the Japanese will be doing all he can to prevent Spies from breaking away.

Unfortunately for the Ducati Xerox star, he missed the July Imola test due to his British round injuries, although he may soon be able to count on the support of team-mate Michel Fabrizio.

The Italian was strong at the July test and, with a 75 point gap to Spies, knows he will soon be called upon to support Haga's challenge.

Hannspree Ten Kate Honda could also play a pivotal role in the race and therefore title battle, having regained competitive form in recent rounds. Rookie Jonathan Rea and Spaniard Carlos Checa have taken five podiums between them in the last four races, including a second win of the season for Rea in Germany.

Stiggy's Leon Haslam had been the leading Honda rider at the start of the year and was once again in podium contention in Germany, before a little misfortune left him sixth and fifth at the flag.

The rider with the most points in the last four races, after Spies, is Aprilia's Max Biaggi with 1-2-5-4 results. The Italian rider and Italian machine will be making their final appearance of the season on home asphalt and looking to make up for relatively tame results at Monza and Misano.

Meanwhile, rumours are flying that Biaggi could be joined by another Italian star this weekend, with reigning 250GP world champion Marco Simoncelli testing the RSV4 at Mugello ahead of what might be a WSBK race debut in place of the injured Shinya Nakano.

BMW's brand new WSBK machine is also gathering pace, with Troy Corser backing up a season's best fifth at Brno with sixth in race two at the Nurburgring. Imola might also see the return of Ruben Xaus following his leg fracture at Brno, but the Spaniard's participation will only be decided at the last minute.

Suzuki Alstare will once again be without injured leading rider Max Neukirchner, whose place alongside Yukio Kagayama will once again be taken Karl Muggeridge.

Fellow Australian Broc Parkes (Kawasaki WSRT) will also be looking for a much stronger showing than at the Nurburgring. He and team-mate Makoto Tamada will have a series of updates and both of them are aiming for top-ten finishes.

Despite three wins in the last four races, Cal Crutchlow (Yamaha) has still not managed to make a decisive break from his World Supersport title rival, Eugene Laverty (Parkalgar Honda).

22 points lie between the two, but this should be sufficient for the Coventry man to administer in the final three rounds of the season. Cal has proved to be the strongest rider out there in any case and Laverty's task is a tough one.

Even though he is still in with a mathematical chance of winning the title, Spain's Joan Lascorz (Kawasaki will just be aiming for his first win to accompany what has so far been an excellent season.

Other key protagonists are likely to be Kenan Sofuoglu (Hannspree Ten Kate Honda), who has won two races so far, and Brno victor Fabien Foret (Yamaha World Supersport). Italian hopes lie with Massimo Roccoli (Intermoto Czech Honda) following his excellent fourth place at the Nurburgring, and Michele Pirro (Yamaha Lorenzini).

It's all change in the Triumph ParkinGo squad, where Chaz Davies comes in as a replacement for Gianluca Nannelli as team-mate to Garry McCoy on the 675 machine.

22-year-old Davies, a former 125GP, 250GP and MotoGP rider - and Daytona 200 winner - will be making his WSS, Triumph and Imola debut this weekend.