Ulster went into the match knowing a win against their interprovincial rivals could see them secure a home semi-final if they were to win.
The fixture also gave fans the chance to say goodbye to 10 senior mens players who were announced to be leaving at the conclusion of the season.
Among those leaving, Duane Vermeulen and Jeffrey Toomaga-Allen started the match in a strong Ulster line-up, led by captain, Alan O'Connor.
Winger Jacob Stockdale was making his 100th cap for the province, and was given a guard of honour as he took to the pitch with his daughter.
Hooker Rob Herring was also making a milestone, equalling the club appearance record of 229 caps, shared with Andrew Trimble and Darren Cave.
The match struggled to kick into gear during the opening 10 minutes, with both sides conceding penalties in the battle for territory.
The fans roared in the 14th minute as tempers flared between the sides in the cagey opening. Ulster's defence had thwarted a Connacht attack close to the home side's whitewash by winning an important penalty and a scuffle followed involving Cian Prendergast and Jeff Toomaga- Allen. It felt like the moment that may have ignited the contest.
Connacht continued to put on the pressure and in the 17th minute it looked line-breaking run had left Connacht with a 2 v 1. Ulster's full back Mike Lowry produced one of the tackles of the season as he clattered into Tom Farrell, who had Caolin Blade to his right. The tackle was almost certainly a try-saving tackle, but the hit forced Mike off the field with an HIA. Stewart Moore came on to replace him at full-back.
Ulster rallied and a nice offload from winger Rob Baloucoune sparked a quick counter attack for the home side who then forced Connacht into a penalty. John Cooney kicked the first points of the match, sending Ulster up by 3.
However, Connacht's captain, Jack Carty replied almost immediately with a penalty conversion of his own to tie the score.
Connacht then scored another penalty after the half hour mark, after a punt downfield from Cian Prendergast put Rob Baloucoune under pressure and Ulster were penalised for holding the ball. Carty sent the Westerners into a three point lead at 3-6.
Connacht were getting a lot of joy from winning the breakdown, as Ulster Head Coach Dan McFarland had highlighted their strength in winning loose balls before the match.
It wouldn't be the last Carty kick of the half, as just before half-time, the fly half got his third penalty kick after Stuart McCloskey was penalised.
The away side went into the half with a 3-9 lead.
Ulster came back out for the second half with one change, Jeff Toomaga-Allen coming off for Gareth Milasinovch, who is also leaving the province following the end of the season.
The big prop conceded a penalty minutes into the half and Jack Carty happily teed up his fourth kick of the match. The eyes of Ulster supporters rolled as the kick took a helpful smack off the post as it went through to give the Galway side a 9 point lead.
Ulster supporters breathed a sigh of relief when minutes later, following Connacht pressure in Ulster's 22, Cian Prendergast touched down past the whitewash. However a TMO check confirmed there had been a knock on by Caolin Blade.
Dan McFarland then rang the changes as off came Nick Timoney, Kieran Treadwell and Rob Herring for Jordi Murphy, Sam Carter and Tom Stewart.
The changes made a positive impact as after the hour mark, Ulster got their maul going and were spurred on by a deafening Kingspan Stadium.
OFX 22/23 Top Try Scorer, Tom Stewart, started to drive the maul towards a tiring Connacht defence and Ulster scored the first try of the match, when Alan O'Connor crashed over the whitewash to give the Ulstermen hope. Cooney added the extras to narrow the score down to a two point game.
Winger Craig Gilroy then came on to make what would be his final match at the Kingspan Stadium after 13 years of playing for his boyhood province.
Driven on from the crowd, Ulster were getting close to their second try of the evening. A burst from Rob Baloucoune into the Connacht 22 found Duane Vermeulen, who couldn't keep the ball in play but won Ulster a lineout after the ball hit Mack Hansen.
Feeling like it was the moment, Ulster drove their maul but were held up by a stubborn Connacht defence who forced a penalty.
Despite more Ulster pressure, Connacht managed to gain territory and won another penalty, this time in Ulster's 22. Jack Carty made a vital fifth kick of the match to ensure Ulster needed a try in the last few minutes.
Ulster fans hearts were in their mouths as replacement scrum half Nathan Doak kicked to the corner giving Ulster one last maul.
Despite their best efforts, Connacht managed to make a game winning turnover and end Ulster's season in disappointment.
FT score: Ulster 10-15 Connacht.
BKT Player of the Match: Shamus Hurley-Langton
Scorers:
Ulster:
TRY:O'Connor
CON: Cooney
PEN: Cooney
Connacht:
PEN: Carty
Ulster:
(15-9) Lowry; Baloucoune, Hume, McCloskey, Stockdale; Burns, Cooney;
(1-8) Sutherland, Herring, Toomaga-Allen; O'Connor (capt), Treadwell; McCann, Timoney, Vermeulen.
Replacements: Stewart, O'Sullivan, Milasinovich, Carter, Murphy, Doak, Moore, Gilroy.
Connacht:
(15-9) O'Halloran; Porch, Farrell, Aki, Hansen; Carty, Blade;
(1-8)Buckley, Heffernan, Bealham; Murphy, Murray; Hurley-Langton, Oliver, Prendergast.
Replacements: Tierney-Martin, Duggan, Aungier, Dowling, Butler, Marmion, Daly, Ralston.
Referee: Andrew Brace<br>
AR1&2: Frank Murphy, Eoghan Cross<br>
TMO: Brian MacNeice