Dylan Easton scored for the hosts at their Penny Cars Stadium home ground on 44 minutes, with Kerr McInroy following suit on 57 minutes and Callum Smith on 64, but Saturday’s game could easily have gone the other way had Peterhead been more alert when opportunity knocked, said McDonald, 23.
“We just kind of lost avoidable goals,” he told the club’s Facebook page.
“It probably wasn’t good enough today.
“The goal before half-time killed us a wee bit.
“That’s what football’s all about, isn’t it – taking your chances when they come?
“Unfortunately we didn’t take them and we got punished for it.”
McDonald helped get a goal back for Peterhead in injury time with a long ball forward put in his own net by home goalkeeper Max Currie but it was too little too late, leaving the scoreline at 3-1.
That win took Airdrie to the top of the League One table, on 23 points from 13 games, and leaves the Blue Toon third from bottom.
They’d headed south to North Lanarkshire hoping to extend a four-game unbeaten run and kept the Diamonds in check for all but the final seconds of the first half, but a defensive slip-up allowed Easton to put the hosts ahead just before the interval whistle blew and they stayed in front from then on.
Peterhead had chances to get back into the game in the second half but they went begging, leaving McDonald and boss Jim McInally to reflect on what might have been with a bit more composure in front of goal.
Hamish Ritchie had two chances one after the other to get his side on the scoresheet but both those efforts were blocked.
Just after the hour mark, Josh Mulligan looked certain to find the back of the hosts’ net after collecting a low Flynn Duffy cross at the back post but put his shot wide.
Refusing to throw in the towel, Russell McLean fired a shot over Currie with 13 minutes left to play only to see it hit the crossbar.
Substitute Derek Lyle also volleyed a Mulligan cross over before a Currie own goal finally got the visitors on the scoresheet.