The Rangers spoiled the 19th birthday of rookie goaltender Marc-Andre Fleury.
The reigning NHL Offensive Player of the Week, Rucinsky recorded his second two-goal game of the season and continued to click with linemates Bobby Holik and Alexei Kovalev, who collected two assists apiece.
He scored twice against Ottawa on Sunday and has six goals and nine assists in his last 12 games.
Rucinsky opened the scoring with 5:04 left in the first period by finishing a solid end-to-end play with his Holik and Kovalev. Fleury kept the Penguins in it in the second period, but Rucinsky sparked a three-goal flurry 3:34 into the third.