Curtis Allen's second-half header denied Portadown victory in the Premiership clash at the Showgrounds.
Darren Murray gave the visitors a 30th minute lead from a penalty after he was tripped by Kyle McVey.
The game came to life after the break and Ports defender Ross Redman hit a post before Allen headed in on 73 minutes from Ryan McIlmoyle's cross.
Coleraine almost won it in injury-time when David Miskelly tipped over Aaron Canning's dipping strike.
There was a lack of goalmouth action in a dour first half although Portadown edged affairs and were good value for their lead at the break.
Coleraine lacked a cutting edge in the absence of Stephen Lowry but they improved on the restart and Keith O'Hara headed off the line from a Bannsiders corner.
Joel Bradley went close for the hosts while Ports striker Richard Lecky sent his header straight at Michael Doherty.
Allen's close-range header set up a thrilling finish and Murray mis-hit when well placed before Miskelly's save to keep out Canning's effort in the dying seconds.
Coleraine slip one place to fourth while Portadown remain eighth.