From: jttp://www.edge-online.com:

Microsoft's Xbox 360 scored a notable victory in Japan during the week ended August 10, shifting almost 25,000 units to outsell the PS3 2.5-1.

The console's jump in popularity - it sold 5,359 units the previous week - was no doubt fueled by the release of Namco Bandai's Tales of Vesperia, which debuted at No4 in the software chart after selling 108,000 copies.