The hosts started the game brilliantly and raced into a strong 19-point lead after half an hour. After five minutes, Euan Rooney scored and Falkirk didn’t look back, with John Joe Nelson and Gregor Dodd also scoring, plus two conversions putting them into a strong lead.
He said of the performance: “We’re out on our foot now, to be honest, we’re done.
"It has been a long season and the breaks haven’t helped, the way they have fallen.
"We lost some big players like Stefan Yarrow and Ewan Rooney, who has now retired.
Green energy is the goal for Little Kerse hub after SP Energy Networks' funding
We need to forget about Saturday's defeat quickly, says Falkirk midfielder Nesbitt
Boxing: Sparta's Thomas O'Reilly earns Scotland call
Diamonds shine as ten-man Falkirk falter in heavy defeat
'Things did conspire against us' - Boss John McGlynn on Falkirk's second-half display
"After 20 minutes, we just lost control, despite being in total control. They had no answers to what we were doing and it was whatever score we wanted it to be.
"We were playing the way we can and everything was going so well until a break in play due to one of the injuries and we lost focus from that point.
"Players just looked spent and I can’t really say what happened because it was so bad.
"They ran out worthy winners and 43 unanswered points is totally unacceptable.
"I don’t want to say it was a dead rubber because we are right beside each other in the league but we both can't go up or down.
"It came down to who was the most motivated and, fair play to them, our weak tackling didn’t help either.”
Falkirk now finish the season against league winners GHK.
The 2nd XV won 46-25 against Panmure to go nine unbeaten as they push on with their late surge for the title.
Grieve was pleased to see the young players see out a tough match.
He said: “They have a lot of younger guys and we were just too strong for them on the day.
“Our finishers and backs ran rings round them and we looked very good.
“We had a small blip after the interval when they got a few scores but, outwith that, we dominated.
“It was worthy victory and the title march for them is still on, which is great. With three to go, they have a real chance.”