LaRose scored late in the first and second periods to help the Hurricanes recover from a 2-0 first-period deficit.
The Hurricanes scored four times on their first 19 shots against Curtis McElhinney despite continued struggles on the power play. Carolina was scoreless on three man-advantages Tuesday, dropping to four for its last 77 on the power play.
LaRose scored his 14th and 15th goals of the season for his first two-goal game since Nov. 17, also a home victory over Ottawa, which has lost seven consecutive meetings at the RBC Center.
Erik Karlsson, Colin Greening and Marek Svatos scored for Ottawa, which led 2-0 in the first period.
Greening gave the Senators the lead after Ward denied Jason Spezza on a breakaway. Svatos corralled his own shot off Ward and scored with 6:20 left in the first.
Ruutu and LaRose then scored 25 seconds apart to tie it. Ruutu redirected Jussi Jokinen's dribbler at 14:07. LaRose then took a pass from Joni Pitkanen and fired the puck past McElhinney, who made 20 saves.
Notes: Carolina improved to 23-1 when leading after two periods, while Ottawa fell to 1-23-4 when trailing after two. ... Pitkanen, who had a first-period assist, has 25 points in his last 28 games (11 goals, 14 assists). ... Carolina's penalty kill has been solid of late, killing off 44 of the last 49 penalties. ... The two-goal first period marked the first time the Senators had scored more than one goal at the RBC Center since their last win in Raleigh, 6-0 on Dec. 12, 2007.