|Connacht (17) 30|
|Tries: Aki, MacGinty, Healy Cons: Ronaldson 3 Pens: Ronaldson 3|
|Ospreys (15) 22|
|Tries: John, Baker, Webb Cons: Davies 2 Pen: Davies|
Connacht made it five wins in a row in all competitions by beating the Ospreys in Galway and extending their lead at the top of the Pro12 to six points.
Bundee Aki and AJ MacGinty scored early tries for the hosts, with the league's leading scorer Matt Healy adding a third touchdown after the interval.
Ben John and Dan Baker crossed for the visitors before the break, while Rhys Webb added his side's third try.
The Ospreys were going for a fourth straight win in the competition.
In the end, they left the Sportsground empty-handed and lie seventh in the table, with a lot of work to do to make the play-offs.
Flying start for Connacht
Connacht flew out the blocks and, after they spread the ball through the backs, Aki went over inside the first minute and Craig Ronaldson converted.
But Sam Davies didn't have to wait long to hit back for the visitors, who were awarded a penalty at the breakdown, and he duly made it 7-3 from the tee.
The hosts returned with interest but when Tiernan O'Halloran was dragged into touch inside their own 22 after 10 minutes, the Ospreys had a chance to clear their lines.
Ben Marshall had other ideas, though, stealing the lineout before Niyi Adeolokun made a sharp break and fed MacGinty to score, Ronaldson slotting the extras from by the touchline.
The game's flying start was not over, however, and before the quarter-hour mark Ospreys had their first try, John crossing over after a quick-tap penalty.
The conversion bounced back off a post but just 10 minutes later they were ahead, Baker dotting down after waves of Ospreys attacks and Davies' extras making it 15-14.
Ronaldson - on his 50th Connacht appearance - restored the lead with a penalty shortly before the half-hour mark and that was the way it stayed until the break, despite the Irish province pressing for a third try in the half's closing stages.
Ronaldson on target with penalties
Connacht showed their intent by kicking a string of early second-half penalties to the corner but Rodney Ah You spilt the ball forward and the Welshmen cleared their lines.
It was another stolen Ospreys lineout that set up Connacht's third try, Daniel Qualter the thief before Ronaldson fed Healy to spin away from his tackler and score.
Ronaldson converted but just three minutes later Rhys Webb flew between the Connacht posts to reduce the deficit, Davies' conversion making it 24-22.
A Ronaldson penalty eased the gap to five points and Davies thought he had wiped it out altogether on 65 minutes only for the TMO to rule double movement.
Ronaldson made it eight from the tee, after a superb Aki break had taken Connacht out of their own 22 and into Ospreys territory, before Ospreys wasted a golden opportunity.
Olly Cracknell was hauled down shy of the whitewash but, when the ball was recycled, Webb's pass couldn't find either of the players waiting on the blind side with a clear passage to the line.
Connacht: Tiernan O'Halloran; Niyi Adeolokun, Bundee Aki, Craig Ronaldson, Matt Healy; AJ MacGinty, Caolin Blade; Denis Buckley, Tom McCartney, Rodney Ah You, George Naoupu, Aly Muldowney, Sean O'Brien, Jake Heenan, John Muldoon (capt).
Replacements: Robb for Ronaldson (75), Marmion for Blade (32), Loughney for Buckley (71), Heffernan for McCartney (73), Bealham for Ah You (58), Qualter for Marshall (41), Connolly for Naoupu (62).
Not Used: Poolman.
Ospreys: Dan Evans; Jeff Hassler, JJ Engelbrecht, Josh Matavesi, Ben John; Sam Davies, Rhys Webb; Paul James (capt), Sam Parry, Dmitri Arhip, James King, Rory Thornton, Joe Bearman, Olly Cracknell, Dan Baker.
Replacements: Watkin for Engelbrecht (6), Walker for John (67), Leonard for Webb (72), Thomas for James (64), Otten for Parry (61), Jarvis for Arhip (52), Bernardo for Bearman (52).
Not Used: Collier.
Referee: George Clancy (IRFU)
Assistant referees: Andy Brace, John Carvill (IRFU)
Citing commissioner: Tim Lowry (IRFU)
TMO: Jude Quinn (IRFU)