Angus O'Brien struck the post with a last-ditch drop-goal attempt as Newport Gwent Dragons fell to a 19-17 Guinness PRO12 loss to Treviso on Friday night.
Sam Davies kicked 17 points as Ospreys came back from a poor first-half performance to seal a crucial Guinness Pro12 win over Edinburgh at the Liberty Stadium.
Leinster and Ireland prop Cian Healy has signed a new three-year Irish Rugby Football Union contract, which will see him remain with the province until the end of the 2019 World Cup.
Robbie Henshaw has opted to leave Irish province Connacht for Pro 12 rivals Leinster this summer, on signing his first Irish Rugby Football Union (IRFU) national contract.
Wales scrum-half Rhys Webb made a successful return from injury as the Ospreys won 21-17 to become the first team to beat Munster in Cork since January 2013.
Scarlets were grateful to a late penalty from replacement fly-half Aled Thomas as they snatched a 22-21 victory in a gripping Guinness Pro12 tussle at Parc y Scarlets.
Ulster notched up their third consecutive PRO12 win to keep them set for a top-four finish as they just about overcame Glasgow Warriors 13-10 at a damp Kingspan Stadium.