The Norwegian was barely in the picture when he missed a short putt and made a bogey on the 15th but he finished birdie-eagle-birdie to sign for a 66 and post the target at 12 under.
Bland joined him in the clubhouse with a birdie-birdie finish of his own in a 68, with two-time champion Rory McIlroy finding water on the last to fall out of the play-off.
Hovland made a two-putt birdie on the first trip back up the 18th and when Bland failed to get up and down after finding a tricky lie with his second, it was the 24-year-old who was left holding the trophy at Emirates Golf Club.
Hovland becomes the first Norwegian to win a Rolex Series event and adds this title to his maiden DP World Tour victory at the 2021 BMW International Open.
It is his third win in five starts after back-to-back victories in November and December at the World Wide Technology Championship at Mayakoba and Hero World Challenge, and could move him up to third in the Official World Golf Ranking.
"This is pretty wild. I didn't really think this was possible going in today," said Hovland, who started the day six shots off the lead. "I knew I had to shoot a really low number but a lot of things had to go my way and I'm thankful that they did.
"I'm pumping right now. It's a little bit surreal and it's hard to kind of calm yourself a little bit but you've just got to rely on all the shots that you hit and just go back to what you know.
"I was fuming after the three-putt on 15 and thought that was it and I knew I just had to try to finish off well and get a nice position for the week. I rolled a really long one on 16 and then on 17 and, hey, we got a shot."
McIlroy found sand off the tee for a bogey at the first and while he was in the waste area down the right off the sixth tee, he managed to find the green and hole from 18 feet
I knew I had to shoot a really low number but a lot of things had to go my way and I'm thankful that they did
The Northern Irishman then made a 29-footer on the next to join the lead as Bland made a big move around the turn.
The Englishman had bogeyed the sixth but he holed a chip on the ninth, made an up-and-down from the sand on the tenth and then holed from the sand on the next for a hat-trick of gains to catapult himself within one.
McIlroy holed a clutch putt for bogey on the tenth after taking a drop in the waste area but hit back from 24 feet on the next and led alone as overnight leader Harding found sand twice, played a second poor bunker shot and then failed to get up and down in racking up a triple-bogey.
He would soon have company, however, as Hovland picked up four shots in his last three holes to surge up the leaderboard.
He had put an approach to six feet at the first and made a two-putt birdie on the par-five third but bogeyed the fourth before hitting a smart approach into the next and holing a 25-footer on the eighth to turn in 32.
His chances looked to have gone when he three-putted the 15th but he holed from 35 feet on the next and then drove the 17th and made a 33-footer for eagle to tie the lead.
McIlroy played a poor second on the 13th but got up and down from the bank for a birdie to edge back ahead, with Hovland completing a two-putt birdie on the par-five last to join him and set the target.
Bland was not done yet, however, and after getting up and down for par on the 15th and 16th, he did it again for birdie on the 17th and 18th.
McIlroy needed a birdie over the gettable final two holes but he had to make a remarkable par from the bushes at the 17th and found water on the last for a bogey that sent Bland and Hovland back up the last.
Harding signed for a closing 76, Meronk - who had also held the lead in the early stages of day four - carded a 72 which was matched by Hatton, Van Rooyen finished with a 73 and Horsfield recorded a 67.