Ayr moved up a gear at the resumption, with energetic play by captain Rollo Press and replacement Declan Bryce.
Smith and prop Jack McDougall were jinking their way through the defence until Jacobson darted over for a try that Gaw converted. 12-6.
Flankers Mitchell Wyllie and Olly Mossie had been instrumental at the break down and Black was getting in on the act too before Gaw stepped up to kick a penalty. 15-6.
Highland got a few good turnovers but couldn't clear, with Hutton secure under the high ball. Again, it was patience that helped Ayr and they eventually breached the defence for McDougall to score. Gaw's conversion hit the post but went over. 22-6.
Highland didn't let their tails drop and showed pleasing creativity to make their way into Ayr's half with a deft chip.
Despite strong tackling by Ayr prop Craig Miller, Highland found the try-line, winger Jack Doherty going over. Carson's conversion just cleared the crossbar. 22-13.
There were exciting bursts by Gaw and replacement Harris, who, like Harry Ledgerwood and the three Jacks of Yuille, Rennie and Burns, made a real impact from the bench.
It was another substitute, Kerr Borland, who barged through the Highland defenders to get Ayr's fourth try after they had twice been held up. Gaw was on song with the boot, converting with ease. 29-13.
There was just time for a last try as Black raced off from the fifty-metre line and dotted down to the delight of his team-mates and the travelling support. Gaw again converted. 36-13.
It was a game fit for the main pitch at BT Murrayfield and both teams can proud of their high standard of rugby.
Final score: Ayr U16s 36 Highland U16s 13.
- Elena Hogarth.
Photos copyright Alan Graham.