Sidney Crosby, Maxime Talbot and Ryan Whitney for the Penguins scored for Pittsburgh, while Antoine Vermette, Daniel Alfredsson and Wade Redden scored for Ottawa.
The victory gives each team 92 points, with Ottawa having one more victory and the Penguins holding a game in hand.
Using his backhand, Ruutu tucked the puck past Ottawa goalie Ray Emery as the second Penguins shooter in the shootout. Ruutu was used in the shootout for only the second time this season since replacing Evgeni Malkin in that role last week. He is now 3-for-6 in the shootout.
Penguins goalie Marc-Andre Fleury stopped Mike Comrie, Dean McAmmond and Vermette to improve to 9-5 in shootouts this season.
Pittsburgh was on its way to its fifth win in a row, holding a 3-2 lead with a two-man advantage with seven minutes left.
But after killing off 56 seconds of a Pittsburgh five-on-three, the Senators got a holding the stick penalty called on Malkin.
After playing 65 seconds four-on-four, Redden scored his seventh goal of the season a second after the power play began.
Fleury did not see Redden’s shot from the point until it went between his legs.