It was world number one Nadal’s 61st career title and took him to eighth on the all-time list, passing Andre Agassi.
“I never had the chance to win here before. I had match points against Davydenko in the final a few years back,” said Nadal, who was runner-up to Russia’s Nikolay Davydenko in 2010.
“I’m happy to start the season like this, it’s the first time I have won a title in the first week of the year and it’s a great way to start the season.”
Nadal took his record over Monfils to 9-2 with the Frenchman having achieved both his wins over the Spaniard in Doha, in 2009 and 2012.
It was a fine start for Nadal to a year in which he hopes to ward off Novak Djokovic’s challenge for the world number one spot, and in a month when he hopes to regain the Australian Open title after a five-year interval.
His standard rose increasingly as the two-hour contest wore on, and his baseline rallying gradually became tenaciously indestructible, its peak coming in the fourth and fifth games of the final set.
This was when he made a crucial break of Monfils’ serve, and followed it by recovering from love-40 down to saving five break points altogether and consolidate his match-winning lead.
That fifth game was punctuated by moments of drama when Monfils thought he had earned a sixth break back point, only for a line judge to call Nadal’s over-hit backhand drive in.
TV replays confirmed that the shot was indeed out, but Monfils had missed his chance to appeal to the Hawkeye video replay system because he had continued the rally for another stroke.
Two days ago Monfils defeated title-holder Richard Gasquet and altogether scored four express victories which did indeed suggest that for the Guadeloupe-born Frenchman the best, at the age of 27, may yet lie ahead.