Ireland scrum half Kieran Marmion made a timely return following ankle surgery as Connacht saw off the Cheetahs 25-17 in an entertaining Guinness PRO14 encounter at the Sportsground.
Playing for the first time since Ireland's November win over New Zealand, Marmion came on for the final 22 minutes, during which Shaun Venter's searing breakaway try brought the Cheetahs level.
A Jack Carty penalty and Connacht captain Jarrad Butler's decisive 78th-minute try then sealed an important victory in this Conference A duel.
Andy Friend's men are now back up to third in the table, but they did it the hard way as the Cheetahs led 12-10 at half-time.
Sibahle Maxwane took his Championship-leading haul to 11 tries and his back-three colleague Louis Fouche also touched down, with Tom Farrell, fresh from his Six Nations squad call-up, replying in the 24th minute.
Tom McCartney's 45th-minute maul try put Connacht ahead for the first time and, despite Venter's jet-heeled response on the hour mark, the Irish province had the better of the final quarter as they completed a first-ever double over the Cheetahs, following December's 21-17 win in Bloemfontein.
The South Africans blew their first try-scoring opportunity of the night, Maxwane doing the hard work in gathering his own kick on the left wing, but the two-on-one was not converted as Carty swooped in to intercept the pass.
There was no denying the flying winger a couple of minutes later as he grounded Nico Lee's well-weighted kick following a William Small-Smith break.
Responding to Tian Schoeman's conversion, Carty's 16th-minute penalty got Connacht off the mark but the Cheetahs' pace out wide continued to cause problems for the home side.
Good hands between Lee, Fouche and Small-Smith sent the latter darting up the right touchline and his final pass put full-back Fouche over for an unconverted score and a 12-3 lead.
Stephen Fitzgerald did well to force a Connacht lineout from the restart, and after the forwards chipped away, Farrell took a great line onto a Carty pass to beat the first defender and then stretch out of a tackle to score his fifth PRO14 try of the season.
Carty converted and the two-point gap remained in place up to half-time despite Cheetahs centre Lee seeing yellow for a high tackle.
Connacht were the aggressors on the resumption, the pack winning a scrum penalty and flanker Colby Fainga'a securing an important turnover.
The pressure told when Butler won the subsequent lineout over giant lock JP Du Preez and a well-executed drive ended with hooker McCartney plunging over. Carty converted to give Connacht a 17-12 advantage.
The momentum appeared to be behind the westerners now with a couple of further turnovers, but the Cheetahs levelled with a smashing try out of nothing, pouncing on a loose ball off a Connacht ruck and releasing scrum-half and captain Venter, who showed great pace to sprint clear from 70 metres out and cross in the left corner.
The difficult conversion was missed and Connacht duly rallied, with man-of-the-match Ultan Dillane stealing another lineout.
Carty moved them back in front with a well-struck penalty, eight minutes from the time, and Butler then swatted away Small-Smith's attempted tackle to go over in the left corner, taking away the visitors' losing bonus point in the process.