The 26-year-old grabbed his first senior goal from close range to give the Fir Park side an away win over Livingston and, after his eight-month battle back from glandular fever, his teammates and gaffer could not contain their delight.
“That goal meant everything to us all,” Alexander said. “You could see the way the boys celebrated with him on the pitch. And they are all over him in the dressing room. He’s a fantastic lad.
“We thought it would be his type of game today and we needed his energy and bite in midfield but I’ll be honest, we didn’t expect him to come up with the winner!”
It came with just 11 minutes remaining and the visitors, who had overhauled Livingston’s early lead, worked hard to see the game out and ensure Grimshaw’s surprising input counted for something.
“He made a great run into the box off the blindside of his opponent and he gets his luck by getting into the right area,” Alexander added. “He is a fantastic lad and everyone loves him. It’s a great day for him. If we can get him three inches from the goal week in week out, he might have a chance to score more!
“We said at half-time we would have to go and show what we’re about. It is the ultimate test coming to Livingston and going 1-0 down. We had to make it happen and we started the second half on the front foot, got the equaliser and went on to score the winner.”
Alan Forrest’s opener had been cancelled out by Tony Watt but the ease with which the Motherwell striker was able to make that happen, followed by the home side’s inability to track Grimshaw and deny him the winner, left Livi boss David Martindale seething.
“I don’t think the way we defended our box we deserved to take anything from the game, if I’m honest. We can’t defend the way that we did. We gave away two cheap goals. In open play I don’t think we were that bad and probably created the better chances.
“I’ve already made the boys watch the two goals! I wasn’t going home and waiting until Monday to show them that. It wasn’t good enough.”