Samsung Electronics today reported that Q4 was its most profitable quarter ever, thanks mostly to skyrocketing smartphone sales. Samsung is projected to have shipped 35 million smartphones in the fourth quarter, after surpassing Apple in Q3 as the world's top smartphone purveyor, Reuters reports. Those sales helped fuel a $4.5 billion profit, beating analyst expectations, which had been around $4 billion. Analysts expect Samsung to extend its lead over Apple this year, with one firm predicting that it sells as many as 170 million smartphones, compared to an estimated 95 million sold in 2011. (More Samsung stories.)