Ronaldson gets his kicks in Connacht's triumph
Connacht 26 Ospreys 15
Allen Clarke's first Guinness PRO14 game in charge of the Ospreys ended in a 26-15 defeat to Conference A rivals Connacht at the Sportsground.
Flanker Eoghan Masterson's try before half-time gave Kieran Keane's men a 13-5 lead, as they looked to make it seven successive home wins in all competitions.
Apart from Dafydd Howells' 18th-minute try, Connacht's defence frustrated Ospreys.
Ospreys coped well during Hanno Dirksen's sin-bin period, Sam Davies swapping penalties with Connacht's Craig Ronaldson, before tries at either end from Tom Farrell and Reuben Morgan-Williams. Ronaldson sealed victory with his fourth penalty.
Fly-half Ronaldson converted the second of two early penalty attempts for a 3-0 lead.
Connacht came under pressure with Tiernan O'Halloran and Andrew Browne both leaving injured, and finding space out wide, Ashley Beck and Kieron Fonotia combined to release Howells who produced a fine finish.
Ronaldson kicked Connacht back in front with a 24th-minute penalty, and the Ospreys were stung by a try via a late lineout opportunity.
The home forwards carried strongly, before Blade fed Masterson to drive low and score, with Ronaldson converting.
The Ospreys' task grew more difficult after Dirksen saw yellow for a late tackle 52 minutes in.
Davies pulled a penalty wide before redeeming himself to close the gap back to 16-8, with Dirksen returning. However, poor defending from Davies and Beck saw Farrell dart clear for a 68th-minute try, converted by Ronaldson.
Although Habberfield's replacement Morgan-Williams raised Ospreys' hopes by scrambling over three minutes later, it was fittingly left to Ronaldson's left boot to sew up the result and complete his own 16-point haul.