This is a crucial period for the PlayStation Vita: several weeks after a price cut that revived the console in Japan, Vita is demonstrating fairly astonishing tenacity. According to Famitsu, Vita remained the No. 2 console in Japan during the week of March 31st with 33,000 units sold, down moderately from 38,000 units in the previous week. The reason this week was particularly important was the debut of a major new title for Nintendo’s (NTDOY) struggling home console Wii U. Alarm bells at Nintendo’s headquarters must be on full blast, because Dragon Quest X sold just 36,000 units and failed to lift weekly Wii U sales higher than 21,000 units from the previous week’s dismal 10,000 unit level.

During the same week, the PS Vita received a far less known title, Muramasa: The Demon Blade, yet it was able to shift 39,000 units. Following the price cut of the PS Vita under 20,000 yen, the Japanese video game market has suddenly shifted to a new equilibrium where two portable consoles dominate the field. In the last week, Nintendo’s 3DS sold 67,000 units and Sony’s (SNE) PS Vita sold 33,000 units. All home consoles sold 21,000 units or less.

The 3DS has received a boost from the popular new Luigi’s Mansion game, but the gap between the top portable consoles has narrowed meaningfully. During the year 2012, 3DS outsold PS Vita by more than a 6-to-1 margin. But even after Luigi’s Mansion: Dark Moon sold 400,000 units over a fortnight, the PS Vita has managed to keep its sales volume at half the 3DS level.

The Vita resurgence more than a year after it debuted could well motivate developers to give it another look. In the meantime, Nintendo is watching the time slowly run out before home console sector focus swings decisively towards the new PlayStation and XBOX models. Wii U’s toehold in the console market is beginning to look tenuous indeed.