The Cardiff Blues scored a late try to stun Edinburgh 19-17, while there were also wins for Glasgow, Munster, Treviso, Ulster, Leinster and the Scarlets in the Pro14.
Cardiff’s victory over the more fancied Edinburgh takes them up to third in the Conference A standings, while Edinburgh are now fourth in Conference B.
Edinburgh reject Jason Harries came back to haunt his old club as he scored a brace to inspire Cardiff to a stirring comeback triumph.
The hosts outplayed Cardiff in the first half, scoring two converted tries to lead 14-0 at the break. That was extended to 17 when Jaco van der Walt added a penalty kick in the 52nd minute. But Cardiff responded with three unanswered tries – including two in the final quarter – to clinch a memorable win.
In other results, the Glasgow Warriors ran in six tries to whack Connacht 43-17, Munster battled to a 19-13 win over the Ospreys, Treviso hammered the Dragons 57-7 to move up to second on the Conference B log and Ulster smashed Zebre 54-7.
Round 16 results:
Edinburgh 17 Connacht 19
Glasgow Warriors 43 Connacht 17
Ospreys 13 Munster 19
Treviso 57 Dragons 7
Ulster 54 Zebre 7
Leinster 59 Kings 19
Scarlets 43 Cheetahs 21