The Reds showed their class and quality by taking 31 points out of a possible 33 in the run-in and Tommy Breslin's side can now celebrate another wonderful league championship success.
Portadown had the best of a nervous first half and should have been ahead at the break.
Chris Ramsey, Gary Twigg and Sean Mackle were all guilty of poor finishing, how different it might have been had they made the most of their opportunities.
With the game delicately poised at 0-0 after the break it was the Reds who edged ahead in this vital game on 53 minutes. Curran was the man on target with a low shot that flew past Miskelly in the Ports goal and Cliftonville had one hand on the trophy.
Portadown almost drew level in the 70th minute, but Darren Murray's shot was saved by Conor Devlin.
Chris Casement went even closer for the Ports in their next attack, the defender hitting a superb 25-yard free-kick which hit the woodwork and Emmett Friars headed the rebound.
However, with seven minutes to go Cliftonville sealed the win and the title when 2-0 to send the away fans into celebration mode for the remainder of the game.
Nearest challengers Linfield needed the Reds to slip up at Shamrock and beat Glentoran in their final home game before the Windsor Park refurbishment programme begins.
In the course of the season I thought we just about edged it and I’m delighted for the players and supporters.
There was a nostalgic note in the air before the game as former greats of Linfield's past were announced to the crowd in the South Stand which is to be pulled down, but that is where the cheering was to end as the Glens won 2-0.
Linfield had a chance to open the scoring on 21 minutes when a Michael Carvill corner was headed on by Mark Haughey but Philip Lowry smashed his volley high over the bar.
Then Aaron Burns set up Andy Waterworth but Elliott Morris had spotted the danger and dashed out to make the save.
John McGuigan almost gave the Glens a first half lead when he connected sweetly but Jonathan Tuffey reacted well to tip the ball away from goal.
Glentoran took the lead early in the second half when a long clearance from Morris fell to Danny McKee and his well struck shot beat Tuffey in the home goal.
Linfield had chances to get back into the game, first Jamie Mulgrew, Haughey and Carvill all going close but the best chance arrived on 85 minutes when Waterworth rounded Morris but when the ball came in there was no Linfield player there to provide the finish.
There was still time for Glentoran to add a second with Jordan Stewart in acres of space to plant a header past Tuffey.
With Portadown crashing to defeat at the hands of the newly crowned champions it left Crusaders the chance to seal third spot and a place in Europe with a 3-1 win at Glenavon.
The Irish Cup final is to the forefront of Glenavon minds these days and they again gave many of their fringe players an outing.
The visitors were quick off the blocks, Declan Caddelll firing his side ahead on one minute. Glenavon did rally and had a couple of half chances but Stephen Baxter's side surged further ahead in the second half with goals from Nathan Hanley (53) and Gary McCutcheon (58).
Glenavon had strong claims for a penalty when second half sub Mark Sykes was clipped in the box, but referee Ross Dunlop waved play on much to the anger of the home fans.
The Lurgan Blues did win a penalty near the end when William Murphy was bundled over and Andy McGrory fired home from the spot-kick.
Warrenpoint moved out of the relegation zone thanks to a 1-0 win over Ballymena at Milltown.
Daniel Hughes was the man on target in the second half to seal three vital points for Barry Gray's side, the strikers 13th goal of the season.
It was just reward for Hughes who had earlier missed a few easier chances and had an effort hit the woodwork.
For Ballymena it was a day to forget with few efforts on goal throughout the 90 minutes.
A 2-2 draw between Ballinamallard and Dungannon Swifts sees the Mallards drop into the relegation play-off spot.
Jason McCartney gave the home side the lead, but this was cancelled out by Matt Hazley.
Dungannon hit the front through Andrew Burns but Liam Martin completed the scoring with a brilliant free kick sixty seconds after going behind.
The play-off place will be decided on Saturday as both Warrenpoint and Ballinamallard go head to head with Premiership survival at stake.
At Clandeboye Park a late goal from Paul Owens gave Coleraine a 1-0 win over bottom of the table Ards.
Owens goal came in the 93rd minute and was the only highlight of an otherwise uninspiring encounter.
Danske Bank Premiership results:
Ards 0-1 Coleraine
Coleraine: Owens (90)
Ballinamallard United 2-2 Dungannon Swifts
Ballinamallard: McCartney (35) Martin (60)
Dungannon Swifts: Hazley (53), Burns (59)
Glenavon 1-3 Crusaders
Glenavon: McGrory (pen 82)
Crusaders: Caddell (1), Hanley (53), McCutcheon (58)
Linfield 0-2 Glentoran
Glentoran: McKee(60), Stewart (88)
Portadown 0-2 Cliftonville
Cliftonville: Curran (54), Garrett (85)
Warrenpoint Town 1-0 Ballymena United
Warrenpoint: D Hughes (62)