Deadly Michael Moffat went for the second-half kill to calm Ayr’s nerves.
His two goals in 10 minutes knocked the stuffing from plucky Clach who had taken a shock interval lead.
Mighty Moff took his tally to nine goals in 13 games and lifted himself to the top of the Ayr scoring charts.
He revealed: “We knew we needed an early goal because the longer it stayed 1-0, the harder and more nervy it would be.
“The goals gave us a big lift and took a lot out of them.
“We were in a lose lose situation. If we won it was what everyone expected, if we lost it was a big shock.
“At the penalty, I watched the keeper move one way and then put it in the opposite corner.”
Boss Mark Roberts claimed he was never worried despite trailing at the break.
“I always felt we were going to get chances and we could have scored six or seven at the end but our decision making at times was poor.
“However, the most important thing is to get through - it doesn’t matter how you play or who you play as long as you do your job.
“Aaron Wyllie was quite accomplished on his full debut. He is one of these boys you’ll not really notice but just does his job.
“Once again, I thought Robbie Crawford was outstanding and covered every blade of grass in the middle of the park.
“Moff was busy, running at people and causing them problems with his movement.”
Clach, who were roared on by a noisy travelling support, stunned Ayr in 14 minutes. Chris Ross nodded down a Struan Scott-Woodhouse cross and Scott Graham dragged the ball back before firing past Ally Brown.
And things got worse with skipper John Robertson hobbling off eight minutes later.
Chances went abegging and there were loud penalty claims right on the interval when Roberts was sent sprawling by Scott-Woodhouse. It looked a clear call but bizzarely ref David Somers didn’t even award a corner.
Ayr should have equalised seconds after the restart when Ryan McStay missed a free header from an Adam Hunter cross.
But the pressure paid off in 49 minutes when sub Ross Robertson crossed from the right and Moffat headed home from close range.
The leveller came 10 minutes later when sub David Winters was brought down by keeper John Campbell as he burst into the box. Moffat wrong footed the keeper from the spot.
Ayr almost got a third when a Hunter rocket from 25 yards smashed off the bar.
And Ross Robertson had left his shooting boots at home as he passed up gilt edged openings to increase the winning margin.
Clach boss Iain Polworth said: “I thought we competed very well and gave Ayr a few problems in the first-half.
“We had a noisy and colourful support who spent five hours on a bus to get here and we didn’t want to let them down.
“We have boys of 18 and 19 who can step up a level from the Highland League and their chance will come. I am sure they impressed the Ayr gaffer.”