PITTSBURGH (AP) -Trent Frederic scored the lone goal of the third period and the Boston Bruins beat the Pittsburgh Penguins 2-1. Frederic gave the Bruins the lead for good at 7:07 of the third. He beat goaltender Casey DeSmith with a wrist shot from the top of the left circle through traffic. David Pastrnak scored his 13th on the power play for the Bruins, who had lost nine of their previous 13 games. It was the Bruins’ second win in their last seven road games following a 5-0-1 stretch away from home.