Heading into the final round with a healthy four-shot lead many were anticipating that Montgomerie would stroll to victory, but the reality was very different and he needed to pull out all the stops to repel a charge from the two-time previous champion David Frost.
It made for an extraordinary - and dramatic - conclusion with no-one knowing if Montgomerie could
respond to the pressure applied by the South African.
Frost made five birdies in his first 11 holes of the third round to reach 13-under-par whilst
Montgomerie failed to improve on his starting score of 12-under.
"Walking up the 12th I knew I was struggling and trailing David," Montgomerie said afterwards.
"But I started to hit fairways and I knew that if I could do that on the back nine I could make birdies."
It helped his cause that Frost's race was run at this point. The South African made bogey
on the 12th and 14th holes, and only broke par again on the last.
Montgomerie, meanwhile, was as good as his word.
He reeled off six straight pars from the 10th tee and then, having weathered the Frost storm, completed the victory in style with birdies on the final three holes.
"This win is right up there," said Montgomerie afterwards.
"The 64 yesterday really set me up, but David Frost pushed me all the way.
"It might look like a comfortable victory on the scoreboard, but I was under pressure," said Montgomerie.
"I really enjoyed that. I was under the cosh, but I came through. That's what we play for."
"I had to be at my best because it was very tough, but to birdie the last three holes gives me an awful lot of satisfaction.
He finished the week on 15-under-par, a tournament record low score, three shots clear of Frost,
and four clear of Paul Eales and Chris Williams who shared third place.
Frost was disappointed to lose but proud of his final day effort.
"I gave it a good go but in the end, the better man won," he said.
"The course is made for Monty so I knew he was going to be tough to beat and so it proved. I'm happy with how I played and I'll be back next year."
The MCB Tour Championship title is the 52-year-old Montgomerie's third European Senior Tour victory of the year and it completed a magical season for him. He was already confirmed the number one golfer on the Tour but when he lifted the John Jacobs Trophy he was a happy man.
"I've won eight European Tour Order of Merit titles and now two on the Senior Tour.
That makes ten and I'm very proud of that number.
"To finish with victory in Mauritius was the perfect end to the year.
When I look back at the year it will be a standout memory for me."
The champion ended his day celebrating with his family who have spent the week with him in the resort.
"What a great place," he said. "We've loved the week."