Murphy, a £1million buy from Crewe in the summer, has struggled to live up to his price tag this season but he was outstanding as Leeds ended a run of five defeats.
Two teams in desperate need of a win after a dismal run of form elected to play five men across the midfield.
Leeds, without a goal in their previous three matches, threatened to break the spell when Murphy burst into the penalty box in the 14th minute but Craig Cathcart completed an immaculately timed tackle.
Murphy, back in the starting line-up after three games on the bench, justified manager Brian McDermott's faith by opening the scoring after 21 minutes.
Tom Lees' high ball was nodded down to Ross McCormack by Matt Smith. McCormack played the ball across to goalmouth to Murphy, who switched it onto his left foot on the corner of the six-yard box and steered it past keeper Matt Gilks for his first goal since the opening day of the season.
It was Leeds' first goal in 319 minutes of football and they continued to put Blackpool's defence under pressure.
Former Crewe midfielder Murphy was again to the fore as he released Scott Wootton down the right and his cross was headed just wide of the far post by McCormack.
Blackpool, with just two wins from their previous 25 matches, should have equalised in the 35th minute.
Tony McMahon motored down the right and the unmarked Neal Bishop powered a header just over the bar from 15 yards.
David Goodwillie, playing alone up front for the Tangerines, sent an angled shot wide with the defence in disarray but Leeds nearly doubled their lead in the 43rd minute.
The lively Murphy was barged to the ground by David Perkins just outside the box and Gilks spilled Michael Tonge's driven free-kick before gathering it to his chest in the nick of time.
Leeds looked vulnerable at the back and Chris Basham just failed to turn Goodwillie's low centre into the net soon after the interval.
Noel Hunt was booed by Leeds fans when he left the bench to replace Smith in the 65th minute and - two minutes later - Blackpool replaced Basham with Belgian Faris Haroun.
Murphy's second goal arrived in the 73rd minute.
Hunt headed on another long ball from Lees and this time Murphy neatly dinked the ball over Gilks with his right foot from eight angled yards.
Leeds keeper Jack Butland denied Blackpool a consolation goal by stretching to tip Gary MacKenzie's header over the bar with five minutes left.