Penske drivers took the top two spots in the two practice sessions in Motegi, Japan ahead of this weekend's penultimate IndyCar event.

Championship leader Will Power topped the opening session ahead of Helio Castroneves, but in the afternoon session it was Ryan Briscoe's turn to shine with Power pushed down to sixth. That was just a single position ahead of his sole remaining title rival, Ganassi's Dario Franchitti.

Franchitti is only 17pts behind Power and is seen to have the edge over the Australian on oval circuits - especially at Motegi, where Power has never raced before. Dario will be looking for help from his team mate Scott Dixon, third on the championship but 83pts off the leader, in order to combat the powerful Penske bloc seeking to propel Will Power to the 2010 title.

The practice sessions were chiefly marked for an early accident involving home favourite Takuma Sato in the number 5 Lotus entry for KV Racing. An oil line failure dropped fluid over the rear tyre of the car which sent it spinning up to hit the SAFER barrier at turn 1 just 15 minutes into first practice, bringing out a long yellow to clean up the debris and collect the spilt fluids. Sato was unhurt but the car sustained significant rear-end damage that meant Sato wasn't back out on track until deep into the second practice session

Sato is joined at Motegi by his compatriots Hideki Mutoh (Newman/Haas) and Roger Yasukawa (Conquest), making his annual appearance in Japan in the car usually driven by Tomas Scheckter.

First practice

1. Will Power Penske 27.1908s
2. Helio Castroneves Penske + 0.1679s
3. Dan Wheldon Panther + 0.1876s
4. Tony Kanaan Andretti + 0.1263s
5. Scott Dixon Ganassi + 0.3660s
6. Dario Franchitti Ganassi + 0.4137s
7. Alex Tagliani FAZZT + 0.4377s
8. Ryan Hunter-Reay Andretti + 0.4430s
9. Ryan Briscoe Penske + 0.4502s
10. Danica Patrick Andretti + 0.4512s
11. Marco Andretti Andretti + 0.4537s
12. Graham Rahal Newman/Haas + 0.5244s
13. EJ Viso KV Racing + 0.5353s
14. Hideki Mutoh Newman/Haas + 0.5875s
15. Roger Yasukawa Conquest + 0.6223s
16. Mario Moraes KV Racing + 0.6398s
17. Paul Tracy Dreyer and Reinbold + 0.6733s
18. Bertrand Baguette Conquest + 0.6846s
19. Alex Lloyd Dale Coyne + 0.7729s
20. Simona de Silvestro HVM + 0.8580s
21. Vitor Meira Foyt + 0.8597s
22. Justin Wilson Dreyer and Reinbold + 0.9308s
23. Raphael Matos De Ferran Dragon + 1.0193s
24. Milka Duno Dale Coyne + 1.5435s
25. Takuma Sato KV + 1.5794s

Second practice

1. Ryan Briscoe Penske 27.2382s
2. Helio Castroneves Penske + 0.0387s
3. Tony Kanaan Andretti + 0.0841s
4. Danica Patrick Andretti + 0.1350s
5. EJ Viso KV + 0.1454s
6. Will Power Penske + 0.1680s
7. Dario Franchitti Ganassi + 0.1912s
8. Marco Andretti Andretti + 0.2250s
9. Ryan Hunter-Reay Andretti + 0.2557s
10. Dan Wheldon Panther + 0.2666s
11. Scott Dixon Ganassi + 0.3086s
12. Vitor Meira Foyt + 0.3809s
13. Alex Tagliani FAZZT + 0.3928s
14. Bertrand Baguette Conquest + 0.4343s
15. Graham Rahal Newman/Haas + 0.4407s
16. Hideki Mutoh Newman/Haas + 0.4696s
17. Justin Wilson Dreyer and Reinbold + 0.4701s
18. Mario Moraes KV Racing + 0.5523s
19. Paul Tracy Dreyer and Reinbold + 0.5545s
20. Alex Lloyd Dale Coyne + 0.5910s
21. Raphael Matos De Ferran Dragon + 0.6190s
22. Takuma Sato KV Racing + 0.6345s
23. Roger Yasukawa Conquest + 0.7022s
24. Milka Duno Dale Coyne + 1.1155s
25. Simona de Silvestro HVM + 1.1992s