Sony's PlayStation 3 took the top monthly spot in the U.S. video-game console sales rankings for the first time since it was launched in November 2006, according to numbers released this afternoon by the NPD Group market research firm. Benefiting from price cuts, the Sony console sold 491,800 units in the U.S. for the month, compared with 462,800 for the Nintendo Wii and 352,600 for Microsoft's Xbox 360.

The numbers show the console race becoming neck-and-neck as the three major players come closer to price parity. NPD analyst Anita Frazier offered this take on the result in a news release.

"All three console manufacturers enjoyed the impact of lower prices on unit sales as the PS3, Wii, and Xbox 360 realized an increase over August of 87%, 33%, and 31% respectively, on an average sales per week basis (keeping in mind September was a 5-week month compared to 4-weeks in August)."

"Compared to last September, the PS3 was the big winner, more than doubling last year's sales. This portrays a very strong consumer reaction to the price decrease as August and September both realized a lift of more than 70% over the prior month. This is the first month that the PS3 has captured the top spot in console hardware sales."

"The best-selling platform overall remained the Nintendo DS which has topped hardware sales for 6 consecutive months."

David Dennis, an Xbox spokesman, said Microsoft believes the PS3 benefited from pent-up demand based on its previous price, and that it will return quickly to more normal sales levels. We've asked Sony representatives for comment, and we'll update this post depending on the response.

Sony dropped the price of the 80GB PlayStation 3 by $100 to $299.99 in August, and introducing a new PS3 “Slim,” with a 120GB hard drive, for the same price. Microsoft in August dropped the price of the 120GB Xbox 360 Elite by $100, to $299.99. (The Xbox 360 Arcade, without a hard drive, sells for $199.99.) Nintendo in September cut the price of the Wii to $199.99. Nintendo had charged $249.99 for the console since its launch nearly three years ago.

In U.S. video game sales, the Xbox 360 exclusive "Halo 3: ODST" topped the NPD charts for the month of September with more than 1.5 million units sold -- more than three times more than the No. 2 Wii Sports Resort and Wii Motion Plus.