James Hinchcliffe and Oriol Servia gave Newman/Haas a one-two in the third and final IndyCar free practice session at Motegi.
The pair moved into first and second - 0.0339 seconds apart - just before Penske's Ryan Briscoe spun and stalled, causing a stoppage.
There was only time for one more flying lap when the session resumed, and Hinchcliffe chose not to get involved in the mad dash out of the pitlane. Though many drivers improved their times, his 1m39.1074s remained unbeaten and he stayed in first place.
Points leader Dario Franchitti (Ganassi) also stayed in the pits and still hung on to third, with Briscoe remaining fourth despite his spin.
Franchitti's team-mate Scott Dixon had followed up his pacesetting morning performance by leading the way for much of this session too. He ended up fifth, ahead of title contender Will Power (Penske).
Mike Conway produced his best showing of the weekend as he led the Andretti Autosport charge in seventh, followed by Helio Castroneves (Penske), Graham Rahal (Ganassi) and EJ Viso (KV). Local drivers Takuma Sato and Hideki Mutoh were 11th and 20th for KV and AFS/Sam Schmidt respectively.
Having got through practice one and two with no stoppages, the final session saw three, with spins for HVM's Simona de Silvestro and KV's Tony Kanaan also causing brief interruptions before Briscoe's incident.
Alex Tagliani, Joao Paulo de Oliveira, Servia and Viso also had minor excursions during the hour.
Pos Driver Team Time Gap 1. James Hinchcliffe Newman/Haas 1m39.1074s 2. Oriol Servia Newman/Haas 1m39.1413s + 0.0339s 3. Dario Franchitti Ganassi 1m39.3183s + 0.2109s 4. Ryan Briscoe Penske 1m39.3354s + 0.2280s 5. Scott Dixon Ganassi 1m39.3486s + 0.2412s 6. Will Power Penske 1m39.5140s + 0.4066s 7. Mike Conway Andretti 1m39.5498s + 0.4424s 8. Helio Castroneves Penske 1m39.5536s + 0.4462s 9. Graham Rahal Ganassi 1m39.5639s + 0.4565s 10. EJ Viso KV 1m39.6098s + 0.5024s 11. Takuma Sato KV 1m39.6641s + 0.5567s 12. JR Hildebrand Panther 1m39.7141s + 0.6067s 13. Ryan Hunter-Reay Andretti 1m39.7489s + 0.6415s 14. Marco Andretti Andretti 1m39.8275s + 0.7201s 15. Charlie Kimball Ganassi 1m39.8486s + 0.7412s 16. James Jakes Dale Coyne 1m40.0156s + 0.9082s 17. Joao Paulo de Oliveira Conquest 1m40.0576s + 0.9502s 18. Sebastien Bourdais Dale Coyne 1m40.0809s + 0.9735s 19. Ana Beatriz Dreyer & Reinbold 1m40.1550s + 1.0476s 20. Hideki Mutoh AFS/Sam Schmidt 1m40.1907s + 1.0833s 21. Alex Tagliani Sam Schmidt 1m40.2420s + 1.1346s 22. Tony Kanaan KV 1m40.2927s + 1.1853s 23. Giorgio Pantano Dreyer & Reinbold 1m40.3143s + 1.2069s 24. Simona de Silvestro HVM 1m40.4398s + 1.3324s 25. Vitor Meira Foyt 1m40.6200s + 1.5126s 26. Danica Patrick Andretti 1m40.9025s + 1.7951s