James O'Connor rose unmarked to head home marauding defender Tommy Spurr's pinpoint cross in the second minute at Hillsborough and Darren Potter notched his third of the season with a sweetly-struck left-footed shot five minutes after the interval to give the Owls the points.
Wednesday have now won five of their last seven league encounters under Irvine, voted Championship manager of the month for January last week, and the Scot accepts his task looks easier now than when he arrived at Hillsborough at the turn of the year.
Irvine, whose side remain only two points clear of 22nd place following Reading's win over Plymouth Argyle, said: "It's a terrific effort.
"Five wins out of seven is magnificent in any division, the lads deserve enormous credit for what they've done and a clean sheet was nice.
"But we're still very much in it. A couple of bad results and people are catching up on you. Reading look like they won their game.
"I think this is going to go a long, long way. We still need six wins I believe, but it sounds an awful lot better, six out of 16 than 11 out of 23."
Blackpool's season is in danger of unravelling after they slumped to a third-successive league defeat, with manager Ian Holloway keeping his players locked in the dressing room for an hour after the final whistle.
The Seasiders, two points adrift of the play-offs prior to kick-off, have won only one of their last eight in the Championship, while Holloway's cause had not been helped by the late-night antics of three of his players in a Blackpool nightclub after Saturday's home defeat to Leicester.
A furious Holloway made good his promise to drop Barry Bannan, Neal Eardley and Ishmel Demontagnac for the visit to Hillsborough, but his mood had not improved after this performance.
Despite their recent slump, opposite number Irvine believes the Seasiders' season is far from over.
Irvine added: "Blackpool are a good team. Ian's obviously missing a few key players at the moment, but I like the way he's got them playing.
"We've had a couple of great results against them and that's terrific from our point of view.
"But I still think Blackpool will win an awful lot of games between now and the end of the season and they will be genuine contenders for the play-offs."
Holloway was clearly unhappy after another defeat and accepted his side's display had been affected by his absent players' misdemeanours.
He said: "You saw us play. It meant I had to bring in three people who aren't quite as well rehearsed as those three and we didn't look cohesive.
"We've also had our player of the season (Charlie Adam) suspended. Charlie's a big player for us and we missed him tonight. We missed his energy, his belief and his ability."
When questioned about the ill-discipline of Bannan, Eardley and Demontagnac, Holloway said: "Do I have any regrets? I regret they went out at the wrong time.
"Two of them were injured anyway, so they wouldn't have been playing. What do I regret? Leaving one of them off the trip while two of them were injured?
"No I don't, that's discipline. I did exactly the right thing. My job is to teach them how to be proper young human beings and respect their job and respect what other people think about their job and how much they pay to watch them.
"They should respect that by not going out drinking and dancing until that time in the morning when they're working the following day."