Currie and Melrose picked up victories in the British & Irish Cup, but Ayr were unable to make it a hat-trick of Scottish wins as they lost to Munster.
Chris Leck scored two tries and Rob Verbarkel, Tommy Seymour and James Johnston also crossed the line as Currie beat Swansea 38-21.
Scott Wight kicked all of Melrose's points in their narrow 9-8 win at home against Welsh side Aberavon.
But Ayr were beaten 9-3 on the road against Munster.
Melrose 9-8 Aberavon
Munster 9-3 Ayr
Swansea 21-38 Currie