NPD data shows that the iPhone, backed by its release on Verizon in the US, actually reversed the market share growth of Android for the first time in two years.  This news comes amid mixed information about CDMA iPhones.  Reports surfaced today that CDMA iPhone production was cut in half, yet Android-heavy Sprint said the Verizon iPhone had materially impacted its own sales.

Android still did account for half of all US sales, however.

It appears that the US smartphone race is coming down to two horses.

The Android OS lost ground for the first time since Q2 2009, falling to 50 percent of smartphone unit sales in Q1 2011 compared to 53 percent in the prior quarter. Apple iOS share rose 9 percentage points to comprise 28 percent of smartphone unit sales. BlackBerry OS also lost ground, falling 5 points, to 14 percent.

“The rise of Apple and HTC show how companies can drive change in a mature device market to change the rules of the game,” said Rubin. “The overall success of U.S. market leaders Samsung and LG will be tied to their success in the smartphone market.”

Perhaps the white iPhone will keep the momentum going in the next quarter?