His closing round of 69 for a 15-under-par aggregate total was enough to take the season finale by three shots from David Frost, who for much of the day had looked likely to claim his third win in the event.
But ultimately it was Montgomerie who prevailed, adding the MCB Tour Championship to the US Senior PGA Championship and the Travis Perkins Masters titles he had already claimed, and in the process smashing his own record for winnings in a single season.
The €679,147 he earned was over three times more than Englishman Barry Lane, his nearest Order of Merit rival, and served to underline Montgomerie’s dominance.
But the 52-year-old did not have it all his own way on a topsy-turvy last day at Constance Belle Mare Plage, in Mauritius.
Montgomerie had entered the final round four shots clear of Frost, but a stuttering start – combined with a quite brilliant one from the South African – turned the tables.
After a brace of bogeys from the fifth hole, however, Montgomerie dug deep and clawed his way back into contention as befitting one of golf’s most prolific winners, narrowing the deficit with a birdie on the ninth and then drawing clear of Frost with that late birdie burst.
He said: “This win is right up there. The 64 yesterday really set me up, but David Frost really pushed me all the way today. I had to be at my best because it was very tough, but to birdie the last three holes to win gives me an awful lot of satisfaction.
“When I saw I was one shot behind, I knew I had to knuckle down because David wasn’t going to give it to me. But I managed to hit pretty much every fairway coming in, which is what I knew I had to do.
“The 17th has been extremely good to me this week, and in the end the way I played that hole has won me the tournament. I birdied it the first day, had the hole in one yesterday and then birdied it again today, so I’ve had two putts in three holes and played it in four under. So in the end, that has made all the difference.”
In contrast to Montgomerie’s back nine of 33, Frost’s challenge faltered after the turn as he bogeyed the 12th and 14th holes to surrender the lead. Despite a birdie at the last, Frost could only manage second for the third time in seven appearances in the event.
But he was nonetheless proud to have maintained his incredible tournament record of never having finished outside the top five, saying: “I gave it a good run, but in the end the better man won. This course is made for Monty, so I knew he was going to be tough to beat – and so it has proved.
“I hit a couple of loose shots coming in, and in the end they have cost me. But overall I’m still very happy with how I played, because it’s a tough golf course. We’ll be back next year for another go.”
Third place was shared between Englishman Paul Eales and South African Christopher Williams, who signed for respective rounds of 66 and 69 to finish on 11 under par.