The region had not beaten Ospreys since December 2007, but a first-half try from prop Rhys Thomas and 17 points from the boot of Wales fly-half Rhys Priestland saw them home in a typically bruising RaboDirect Pro12 encounter.
Ospreys had threatened to stage a powerful fightback after trailing 16-3 at half-time, with British Lions prop Adam Jones spearheading a dominant scrum and Barry Davies scoring their only try of the game. But at 16-14, Priestland landed two more penalties to ease the nerves of the 14,756 crowd - a record league attendance for the region.
The 42-13 scoreline may have been flattering but Leinster did enough to outwit a young Ulster side and extend their lead at the top to six points.
Ulster showed huge commitment in defence at a well-attended RDS, but first-half tries from Fionn Carr, Sean Cronin and Leo Auva'a had Leinster 21-6 ahead at the break.
The hosts were nowhere near their best and Ulster hit back with a well-taken try from debutant Chris Cochrane. However, Leinster's forwards dominated the final quarter and a penalty try and further touchdowns from Ian Madigan and replacement Jamie Hagan completed the home win.
Visser turned the game in Edinburgh's favour with two tries in three minutes early in the second half, while Ross Rennie also crossed the whitewash and Greig Laidlaw kicked eight points for the hosts. But Warriors replacement Jackson claimed Glasgow's third try three minutes from time to level the scores.
Jackson was denied further heroics as he missed the subsequent conversion and a last-minute penalty in blustery winds, but the Warriors' unbeaten league run was extended to seven matches.
Scotland head coach Andy Robinson will have been heartened by what he saw, the only real negative when Rory Lamont was taken off on a stretcher and on to hospital for precautionary tests following an awkward landing in the first half.a 23-23 draw at Murrayfield.
John Hayes enjoyed a winning send-off in Munster colours as they earned their sixth successive victory 24-9 over Connacht.
After 14 years and 217 appearances for the province and an enviable collection of European and domestic honours, the `Bull' bowed out in fitting circumstances at Thomond Park.
This was a niggly inter-provincial affair beset by scrum problems and with try-scoring chances at a premium, so two more penalties from Ian Keatley was enough to seal the result.