Albeit by a small margin of 239 units, Microsoft’s Xbox 360 has outsold the PS3 in Japan in the week ending November 4th.

According to numbers from Media Create, the 360 sold 17,673 units in the week in question — a huge jump when compared to the 3,718 units sold in the week prior.

The reason for this increase in sales, you ask ? Ace Combat 6: Fires of Liberation, most likely. Yup, the Xbox 360-exclusive air combat game from Namco Bandai Games faced a rather successful launch in Japan and sold almost 80,000 copies in its first week.

Nintendo’s Wii was still in a league of its own with 37,617 units sold. And the DS and PSP were dominating the top of the chart with 78,599 and 59,714 units sold, respectively.

Outselling the PS3 in its homeland is no doubt glorious news for Microsoft, and we’re betting they’ll be getting some more when Lost Odyssey launches in Japan early December, just like Sakaguchi predicts.