United made a dream start to the new season with a 3-0 rout over Arbroath at Gayfield putting them joint top of League One.
The result is the club’s biggest victory in an opening league game since 1921.
Two well worked first half goals from Michael Moffat set the tone for a rampant Ayr who cruised to victory with Alan Forrest coming off the bench to notch a third.
Roberts made one change from the side that narrowly lost out to Partick Thistle with Josh McArthur replacing the injured Martyn Campbell.
United started brightly and hit the post after just 4 minutes through Michael Moffat who unleashed a thunderbolt which crashed against the woodwork.
The striker wasn’t to be denied after 12 minutes though when Scott McLaughlin charged into the box before squaring the ball to Moffat who was able to open the scoring.
United were on song and it wasn’t long before they doubled their lead. McGowan and Marenghi had a long discussion about what they were going to do with a 25 yard free kick before McGowan neatly chipped the ball through to Moffat who rifled home in front of the travelling supporters.
Every time Ayr streamed forward, they threatened the Arbroath goal with Gordon Pope rattling the crossbar after 28 minutes.
Arbroath did look dangerous on the counter attack though and were close to pulling a goal back through Bobby Linn who was a constant threat throughout for the Red Lichties.
As the half drew to a close, the towering Alan Lithgow nearly made it three for the travelling side when he headed narrowly past the post.
In the second period, Arbroath surged forward and hit the post after 53 minutes before Anthony Marenghi hammered the rebound clear.
Roberts looked to make a tactical change and replaced McArthur with Alan Forrest allowing Pope to play in the centre of defence and Michael Donald at left back.
For the third competitive game in a row, Roberts’ substitutes made a difference with the youngster scoring for United.
After 62 minutes, Michael Donald made a surging run up the left flank before squaring to Forrest. The 16 year old gathered the ball in front of the goalkeeper and opted to dummy a shot before coolly rounding Scott Morrison and rolling the ball calmly into the net.
As the game drew to a close, United toyed with their opposition and were agonisingly close to making it four when Craig Malcolm failed to touch home a tantalising cross.
After the match, Mark Roberts said: “In the first half, we had so many good chances and could have scored more than two.
“In the second half, we caught them out on the counter attack with Moffat and Forrest looking dangerous all the time.
“The composure is ripping out of Forrest. His awareness and touch is absolutely brilliant and he took his goal very well.
“Alan Lithgow was magnificent for us and was the best player on the park for me.
“We won’t get carried away despite the great result.”
Two goal hero Michael Moffat said: “I’ve only been to Arbroath twice in my life and I’ve scored six goals so I enjoy it at Gayfield.
“As well as scoring three, everyone is pleased we kept a clean sheet as we didn’t have many of them last season.
“My new partner up front this season is Craig Malcolm and I like playing alongside him. He’s good in the air and was unfortunate not to get a goal.”
Arbroath: Morrison, Hamilton, Travis, Keddie, Lindsay, Darren Smith, Linn, Chisholm (Cook 62), Yao (Sheerin 63), Bayne, Milne (Martin 77). Subs Not Used: Scott, Sibanda, Bullock, Banjo.
Ayr: Hutton, Hunter, Lithgow, McArthur (Forrest 59), Pope, McGowan, McLaughlin, Marenghi (Shankland 80), Donald, Moffat, Malcolm. Subs Not Used: Wardrobe, Longridge, Roberts, Wyllie, William Muir.
Booked: Pope, Hunter.
Goals: Moffat 13, 17, Forrest 62.
Ref: John McKendrick
By Michael Lamont