And winless Glenrothes now look destined for the drop following the demolition job by the Raeburn Place outfit.
Of Heriot’s triumph over the Broughty Ferry boys at Goldenacre, a thrilled skipper Keith Morton said: “It was a huge result for us following our loss to Carlton the previous week.
“We knew we had get back to form quickly and Forfarshire were always going to pose a strong challenge.
“With the bat we thought we were a few below par but Elliot Ruthven’s opening spell turned the game in our favour and our spinners were as reliable as ever.
“We’re in a great position as a club with all three teams challenging for silverware and we’re all looking forward to the final few weeks of the season and the exciting occasions that lie in store for us.
“I don’t think there’s any pressure on us, it’s just important we continue playing positive cricket and enjoying our days together.”
Chasing a modest 176, Forfs were shot out for only 125, Ruthven accounting for Chris Greaves, Craig Wallace and Michael Leask at the top end.
A superb knock of 118 by Dylan Budge paved the way for Grange’s home-turf success.
Preston Mommsen weighed in with 68 as the hosts surged to 284 for four.
Their Scotland mate Safyaan Sharif was the only Glens man to offer significant resistance with 48 not out.
Charlie Peet was the pick of the Grange attack, taking three for 21.
Arbroath captain Marc Petrie admitted the Lochlands hammering by Carlton was “a bad day at the office which is becoming a bit too common”.
But there was a steely defiance when he added: “I am backing the lads to make it right and turn things around soon.
“We have a young and inexperienced squad who will learn with every win – and even more from the defeats.
“I am still as proud as ever to lead this team.”
Rory McCann hit 85 to send the capital outfit to 260 for six.
The writing was on the Arbroath wall when Petrie and Hayden Laing were out before a run was on the board.
There was no recovery route and they plunged to 82 all out.
RHC Lions claimed a robust four-wicket victory over Watsonians at Myreside.
And Stewart’s-Melville tripped up again at the hands of Aberdeenshire at Inverleith.