Connacht had led for most of contest and secured their bonus-point fourth try in the second period, before Ulster rallied to score two late tries through India Daley and Stacey Sloan, with Vicky Irwin's nail-biting conversion levelling the contest at the death.
The home side looked like they would score a wonderfully worked try through captain, Kat Dane, who was found in space after a great carry from Sophie Barrett. The scrum-half however was tackled well before she could reach the tryline.
Ulster kept up their positive start to the game and put the first points on the board through fly-half, Abby Moyles.
The opening try came for the Westerners via Meabh Deely, after the full-back was found in space by winger Hannah Clarke, who had done well to side step tackles. The kick from the try-scorer was short.
Resetting themselves, Ulster attacked from the restart and attacked the Connacht 22, which led to the home side winning a penalty. Abby Moyles opted to take the three and Ulster led once again at 6-5.
Connacht ended the half on top, after an excellent individual try by their quick back-rower, Faith Oviawe, who couldn't be stopped from her own half as she sped her way to the tryline.
Deely's conversion was missed.
Ulster headed into the break four points behind at 6-10.
HT: Ulster 6-10 Connacht
The second half needed a quick start from Ulster, but the home side were penned back immediately by Connacht, who were moving the ball with speed along their attack. They landed a blow early on, with Laoise McGonagle dotting down in the left corner after a good attack from Connacht.
Ulster needed a moment from somewhere, and it came from superb piece of wing play from Lucy Thompson, the Enniskillen winger showing great footwork and speed to race away from the Connacht defence on the right wing as she sped down the wing for a vital score. The try was unconverted but it gave the crowd in Belfast a much-needed lift.
Connacht then landed another blow, with their bonus-point try. Full-back, Maebh Deely, notching her second after a smart play from a penalty, the full-back catching Ulster off guard in their 22 after a knock on at a scrum. That try and conversion brought the score to 11-25, with it looking like the game was getting away from Murray Houston's team.
Ulster however refused to give in and like last week in Cork, showed fantastic grit despite the scoreline.
Vicky Irwin came off from the bench and immediately provided an impact in play.
Ulster back-rower, Brittany Hogan, made a vital turnover with Connacht aiming for a fifth try and just minutes later that proved important, as an attack from Ulster resulted in India Daley finishing Hogan's drive towards the line. Irwin's conversion narrowed the deficit to seven points.
The drama didn't end there, with Ulster attacking again straight from the restart, with the crowd fuelling their momentum. Another great carry from India Daley got Ulster close to the Connacht whitewash and Stacey Sloan found a gap to drive over, doing well to ground the ball despite the efforts to hold it up from Connacht.
Then, with all the pressure on, Vicky Irwin, showed nerves of steel as she timed her run-up and kicked beautifully to level the scoreline with seconds left on the clock.
The full-time whistle went and Ulster emerged the happier of the two sides after an incredible second half comeback.
With Connacht's lead in the second half, two points hadn't looked likely but Ulster didn't give up and will aim to take that spirit into next weekend against Leinster at Kingspan Stadium.
FT: Ulster Women 25-25 Connacht Women
Player of the Match - Brittany Hogan
Scorers
Ulster:
TRY: Thompson, Daley, Sloan
CON: Irwin x2
PEN: Moyles x2
Connacht:
Deely x2, Oviawe, McGonagle
CON: Deely
PEN: Deely
Teams
(15-9): Lauren Farrell - McCabe, Lucy Thompson, Catherine Martin, Tara O'Neill, Peita McAlister, Abby Moyles, Kathryn Dane (C)
(1-8): Bronach Cassidy, India Daley, Sophie Barrett, Brenda Barr, Cara O'Kane, Moya Hill, Maebh Clenaghan, Brittany Hogan (VC)
Replacements: Christy Hill, Megan Brodie, Ava Fannin, Gemma McCamley, Stacey Sloan, Rachael McIlroy, Paige Smyth, Vicky Irwin
Connacht:
(15-9) Meabh Deely, Hannah Clarke, Orla Dixon, Éabha Nic Dhonnacha, Laoise McGonagle, Nicole Fowley (CC), Grainne Moran
(1-8) Ella Burns, Lily Brady, Megan Collis, Karly Tierney, Grace Browne Moran, Faith Oviawe, Beibhinn Gleeson, Shannon Touhey (CC)
Replacements: Stacey Hanley, Hope Lowney, Roisin Maher, Jemima Adams Verling, Rosie Searle, May Goulding, Ava Ryder