The second half was a revelation as the home side rediscovered their form and took the game to the team just a place below them on the ladder. In the end the victory was decisive and allowed Ricki Herbert's team to equal their winning streak of three matches set in November 2008.
Leo Bertos gathered well on the right, charged, knocked the ball around defender Aziz Behich - who failed to clear as Ifill opened the scoring - crossed deftly to pick out Chris Greenacre who charged between two defenders to head home his fourth goal of the season for a 2-1 54th minute lead.
The tempo continued with several half chances until Ifill made it safe with the goal of the match in the 65th minute. Referee Peter Green waved play on at halfway as the ball was sent wide to Manny Muscat who held the ball up for Ifill who gathered, turned and snapped his stinging shot home.
The only downside in the last 25 minutes was watching Bertos stretchered off after a nasty late challenge by substitute David Williams after replacing Mate Dugandzic.
Eight minutes from time, Phoenix substitute Daniel hit the post with a raking freekick. Ifill swooped to play the ball to Tim Brown but his tap-in was ruled out by the offside flag.
The visitors had a couple of half-hearted late attempts but the Phoenix were in no moody for charity.
The test for Herbert will come in the five games, of the remaining eight, they will play away from home starting with Friday's short turnaround to face Adelaide United in the round opener.
There remains a settled feel within the team. Ben Sigmund and captain Andrew Durante command the defence with Muscat and Tony Lochhead steady on the flanks. Goalkeeper Mark Paston continues to perform well - even if it was an armchair ride yesterday - while up front Ifill is the catalyst with Greenacre his worthy lieutenant.
The midfield continues to battle strongly with American Alex Smith growing more and more into the role in working alongside Brown, Bertos and Dani Sanchez.
The Phoenix will be targeted as the season reaches the business end but with four wins in their last five outings, they have shown they are up to any challenge.
Phoenix 3
Melbourne 1