Lavilla has to finish ahead of the Honda duo to maintain his hopes of the crown, but he in turn has to overcome serious in-team challenges, with Leon Haslam, the only other rider to enjoy a victory this season, eager to build on his current fifth place in the rankings.
The emerging force of Michael Laverty aboard the Stobart Honda adds to the intriguing front-running scrap, with reigning champion John Reynolds, virtually back now to full fitness certain to be pushing hard on his Rizla Suzuki on a circuit where he enjoyed success last year.
Keep an eye also on the Hawk Kawasaki riders Glen Richards and Dean Thomas who are strengthening every race to be long overdue a victory while Scott Smart continues his seasonal rebuilding process aboard the Vivaldi Kawasaki.
Tommy Hill spearheads the Virgin Mobile Samsung Yamaha effort, with Sean Emmett still recovering from an elbow injury, while James Haydon, coming to terms with his Rizla Suzuki, should be asking questions out front.
The race within a race for the British Superbike Cup added further dimensions, with James Buckingham riding the Quay Garage Suzuki looking for more class honours to head off the threat posed by Steve Brogan, Chris Martin and Marty Nutt.
Around the two Superbike races, there is also action counting to the Metabo British Supersport Championship, the British 125cc Championship, the Metzeler Racetec National Superstock Championship and Cup and the Virgin Mobile Cup.
