Cliftonville started the season finale on the front foot with Kirsty McGuinness’ deflected shot, which had wrong-footed stopper Ellie Scott, going narrowly wide.
As the half progressed, both teams cancelled each other out, with the Reds having more possession but the Glentoran defence able to deal with any threat caused.
Just after the half-hour mark, a well-timed pass from Charlotte Havern found Kirsty McGuinness in a good position, with her left-footed effort just off target.
Havern, who recently earned her first senior Northern Ireland cap, continued to be involved when the Reds pushed forward, with Caitlin McGuinness heading her delivery towards goal before the effort was unluckily blocked by her own teammate, Vicky Carleton.
Just after the restart, Naomi McLaughlin had two opportunities in quick succession, but both sailed over the crossbar.
Glentoran defended resolutely and Cliftonville struggled to find gaps with Louise McDaniel and Caitlin McGuinness both having half chances as scoring opportunities remained few and far between.
In the 68th minute the Reds had the best chance when Carleton was gifted a great chance by Caitlin McGuinness, but she was unable to steer her effort on target.
In the final five minutes of the half, Danielle Maxwell couldn’t convert after good build-up play from Kirsty and Caitlin McGuinness before Mia Moore noticed Maddy Harvey-Clifford was off her line and fired just wide.
Chances remained at a premium until the final seconds of additional time when Ellie Scott made a super save to deny Toni-Leigh Finnegan from snatching a late winner.
Jess Foy netted the opening penalty of the shootout before Caitlin McGuinness missed her spot kick.
Demi Vance and Carleton both could not convert before Aimee Kerr and Finnegan made no mistake.
Faye Loughan and Anna Rose Robinson exchanged penalties before Bailie ended her career in style with a powerful effort.