Charnock Richard failed to capitalise on nearest title rivals Blackpool Wren Rovers draw as the Mossie Park outfit lost 3-2 against bottom-of-the-table Norcross & Warbreck.
The table-toppers still need two points to mathematically secure yet another West Lancashire League Premier Division crown.
Dan Morris and Gary Pett had given the home side the lead before Charmock reduced the deficit with just minutes remaining.
Pett then added a third for Norcross & Warbreck but the scoring wasn’t finished as Grimshaw bagged his second.
And after a frantic final few minutes, Norcross held on to seal a battling victory.
The visitors struggled to get their fluent passing game going with Norcross taking advantage of a stiff breeze in the opening stages.
The hosts took the lead after nine minutes when a quickly taken free-kick caught the Charnock defence off guard and Morris ran clear to slot the ball past Gavin Bates.
Charnock re-shuffled their pack with Alex Porter moving up front and Spencer Bibby dropping to the left wing.
But it was Norcross who kept on attacking, and Bates needed to tur a Pett header round the post.
However a minute later, Bates was the victim of an unfortunate bobble in the pitch as Pett’s shot trickled in the net.
Charnock started strongly in the second half with Ash Young, Grimshaw and Andy Roberts all missing chances.
The away side pulled a goal back when Grimshaw converted a Roberts cross.
But in the final six minutes, Pett bagged his second after breaking clear of the defence and slotting past Bates before Grimshaw reduced the deficit once again as he finished a Porter cross, but Charnock couldn’t find the equaliser and Norcross held on.