Last year, the Millbrae men lost in the semi-finals to Melrose and they will be keen to have a day out at BT Murrayfield this time around.
They made sure there would be no shock at Rubislaw, shaking off an early start and long bus journey to get the job done against their BT National League Division One opponents.
Calum Forrester’s men led 32-0 at the interval. Frazier Climo bagged the first try and then Jamie Bova a second. Both were unconverted and it was 10-0.
Adam Prentice then grabbed his first try for the club and young Paddy Dewhirst converted.
Richard Dalgleish and skipper Pete McCallum added tries and Ayr were coasting. McCallum scored a sixth try before half-time.
Robbie Smith scored a converted try after the break for Ayr, as did Danny McCluskey and Gregor Henry. Matt Arnold scored two tries for Aberdeen Grammar, but the visitors were worthy winners.
At Beveridge Park, Kirkcaldy knew that they had a big job on their hands to contain holders Heriot’s.
The Fifers, from two divisions below the Edinburgh side, gave it everything and played some cracking rugby in front of a big home crowd, but Heriot’s used all their experience to progress 36-14.
Dundee HSFP hosted Stirling County, who were missing a few key players and drafted some youngsters onto the bench, but they battled through to win 38-12.