Mo have their spot inside the top-four confirmed, as do the Diamonds, although Ian Murray’s men still have a chance of lifting the League One title.
As things stand, though, there’s a strong possibility Montrose and Airdrie will meet each other in the promotion play-offs and Petrie, speaking following the exciting draw on Saturday, believes his men laid down a marker in their performance.
The Links Park boss said: “It was probably the most entertaining game of the season that I can remember.
"There were two teams who just wanted to win the football match from the first minute which is refreshing to see because we’ve had a few games where it’s been a bit stalemate, turgid and there hasn’t been a lot of quality.
“There were a lot of good performances, no doubt about that.
"We know Airdrie are a right good side and they have real quality all over the pitch.
"Their run since their last defeat tells you that.
"It was important that, if it is Airdrie (in the play-offs), then we set down a marker to an extent.
"If it’s going to be Airdrie then it’s going to be a close game.
There are still three games to play before the play-offs begin with Montrose this week travelling to Clyde.
Seven days later comes a mouthwatering home match against fourth placed Queen’s Park.