Ouch. iPhone Outsells BlackBerry in Canada.

Research In Motion has finally lost its home-country advantage.

The company’s BlackBerry, long a favorite among Canadians, was outsold by Apple’s iPhone last year, for the first time. According to new data from IDC, RIM shipped 2.08 million BlackBerrys in Canada in 2011. Meanwhile, Apple shipped 2.85 million iPhones, easily besting it.

And Canadian sales of the BlackBerry, which account for 7 percent of total shipments of the handset, fell 23 percent in the latest quarter.

A humiliating reversal for RIM’s BlackBerry, which just four years ago was outselling the iPhone in Canada by a nearly five-to-one margin. While losing traction like this among the hometown crowd isn’t a massive strategic defeat, it’s surely a devastating psychological one for RIM, a Canadian success story.

Still, it’s important to note that the BlackBerry remains the dominant smartphone in some emerging markets, like the Middle East and Africa, where 2011 BlackBerry shipments were more than triple those of the iPhone.

RIM reports earnings next week.