The Irishman's winner got Wolves off to a flying start just three months after defeat to the same Rovers side almost cost Mick McCarthy's men their top-flight status.
Ward lashed home a left-foot shot in the 48th minute after Paul Robinson saved Kevin Doyle's penalty and the ball was only half-cleared into Ward's path.
Steven Fletcher had swiftly equalised a debut goal by Mauro Formica in the first half of a match that was a repeat of their survival showdown on the final day of last season.
Wolves started with with new signing Roger Johnson as captain while Rovers boss Steve Kean kept his host of new signings, with the exception of Formica, on the bench.
It was Kean's men who started better and they almost grabbed the lead in the fourth minute when Morten Gamst Pedersen found space on the right to deliver a low cross.
Junior Hoilett stretched his left foot at the far post and looked to have prodded his side ahead, only for Wolves keeper Hennessey to gather in a goal-line melee.
With Rovers still stunned by their near miss, Wolves broke up the other end and Matt Jarvis almost teed up Doyle in the box before the linesman flagged for offside.
Johnson was the first player in referee Kevin Friend's book for a foul on Morten Gamst Pedersen but David Dunn's dangerous-looking free-kick came to nothing with Brett Emerton firing the rebound over the bar.
Jason Roberts' persistence paid off after 20 minutes when he squeezed through two defenders and fed Formica who nudged a left-foot shot across Hennessey and into the net from a tight angle.
But Wolves were level just three minutes later when Matt Jarvis dug out an excellent cross from the right and Fletcher rose in the box to head past Robinson.
Buoyed by their unexpected equaliser, Wolves continued to press and might have gone ahead after 28 minutes when Stephen Hunt blazed just over after some neat play in the box.
Rovers regrouped and, led by the bustling Roberts, forced their way back into the game. Formica had a hopeful penalty appeal turned down after falling under a Karl Henry challenge.
It was Wolves who won a penalty within a minute of the restart when Friend deemed Michel Salgado had hauled down Jarvis close to the by-line.
Doyle's penalty was saved by Robinson low to the keeper's left but the ball was only half-cleared and fell to Ward who lashed home a left-foot shot from just inside the box.
Wolves almost went further ahead after 51 minutes when substitute Kevin Foley crossed to Fletcher who had time to chest the ball down in front of goal before a crucial interception by Steven Nzonzi.
McCarthy's men, looking confident and tenacious, continued to pin the home side back in their own half and already the first murmurings of discontent were evident among the Rovers support.
In a rare chance, Roberts and Nzonzi contrived to miss a David Dunn corner in the Wolves six-yard box and Kean responded by throwing on David Goodwillie for the final 20 minutes.
It was another substitute, Ruben Rochina, who came closest to an equaliser for Rovers in the 75th minute when he lashed a long-range effort just wide.
Goodwillie also came close with a shot on the turn in the 83rd minute but Rovers' quest for an equaliser petered out and the boos at the final whistle suggested a hard season ahead.