Dungannon Swifts ensured their Premiership safety by grabbing a point.
Stevan Lavery headed in the equaliser in the 82nd minute and the point means the Swifts cannot be caught by one-from-bottom Donegal Celtic.
It had looked like Gary Twigg's 67th-minute strike would be enough to give Portadown victory.
The former Shamrock Rovers star pounced from close-range after Kevin Braniff had played a low ball in from the bye-line on the left.
Early in the match Ports skipper Braniff had forced an excellent save from Dungannon keeper Johnny Curran with an audacious chip from an acute angle while defender Gary Breen saw two headers go over.
In the second half Dungannon striker James Costello tested home keeper David Miskelly with a low drive.
At the other end Twigg shot wide after being put in by a Darren Murray pass.