The PS4 was the best-selling console in the US in November.
The victory halts what had been a four-month stretch of wins for Xbox One, prior to which Sony's machine had enjoyed a prolonged stint of dominance.
NPD's official sales data won't be released until next week, but Microsoft's statement failed to include any comment about a November win – something GameSpot cottoned on to before getting confirmation from Sony that PS4 had topped the monthly hardware charts.
"We have seen strong momentum for Xbox One since announcing the new Xbox One S at E3 in June. That momentum continued in November as gaming consoles were once again among the most sought-after products to buy over Black Friday weekend," Microsoft said.
"In addition, we saw record engagement among Xbox One owners on Xbox Live as fans enjoyed new games and great deals. In fact, the total players online on Sunday, Nov. 27 was up 40 per cent compared to last year."
It's always hard to precisely understand what factors shape these trends. Certainly, Microsoft's slimmed down Xbox One S had a bigger immediate impact than Sony's redesigned PS4 Slim. However, with PS4 Pro now here and big discounting for its Slim machine, Microsoft's Xbox One S now faces a battle on two fronts.
Only time will tell whether Xbox One's winning streak was an anomaly or a sign of a more permanent momentum shift. Certainly the recent signs have again been positive for Sony. The only certainty is that both companies will continue to discount their hardware through Christmas. Expect further shake ups when the Xbox Scorpio arrives next year.