The Kiwi had turned a two-shot first-round lead into a three-shot advantage at the midway point and he doubled that heading into day four at Al Hamra Golf Club.
He saw the gap trimmed to two just after the turn as Pablo Larrazábal made a move but Fox signed for a 69 that moved him to 22 under and gave him an ultimately comfortable victory.
Fox's victory is his first in a 72-hole stroke play event on the DP World Tour having claimed the 2019 ISPS Handa World Super 6 Perth title to go with two European Challenge Tour victories.
He becomes the second wire-to-wire winner of the 2022 season after Thriston Lawrence, with the South African lifting the trophy at the weather-affected 36-hole Joburg Open.
The last wire-to-wire winner over 72 holes was Nacho Elvira at the 2021 Cazoo Open supported by Gareth Bale and the last Kiwi to achieve the feat was Michael Campbell at the 2000 Johnnie Walker Classic, which was played in November 1999.
"It was a bit of a struggle today," said the two-time Olympian who now moves into the top ten on DP World Tour Rankings in Partnership with Rolex. "Sleeping on a six-shot lead I did not sleep very well last night and obviously a couple of guys came at me early.
"I was a bit nervous and had that awful feeling in the pit of my stomach all day but I'm very happy with how I played. I hit a couple of great shots coming down the stretch and it was certainly nice walking up the last with my putter in my hand knowing I had six putts for it."
Fox's daughter Isabel was born in December 2020 and the 35-year-old could not wait to get home and see her - after spending ten days in hotel quarantine due to the Covid-19 pandemic.
"I was definitely thinking about the family coming down the last couple of holes, it's pretty big for them," he added. "They've got to come over to Europe every year and it's a little bit harder with a little one now and this win makes it a little bit easier for them to do that.
"I'm a bit disappointed that I missed her walking and I've got ten days in a hotel when I get home to think about that as well and I'm very much looking forward to seeing them when I get out late February."
Larrazábal put his approach to 14 feet at the second and made a two-putt birdie on the par-five third to trim the lead to four as Fox failed to take advantage of the driveable first and the par five.
Fox missed a putt from around a foot to drop a shot at the fourth but for the seventh time this week, he responded with a birdie as he got up and down from the sand on the driveable fifth.
A bogey followed after a poor tee-shot on the the sixth and Larrazábal holed from nearly 40 feet on the seventh to reduce the lead to just two.
Fox took advantage of the par-five eighth and did well to make par on the ninth and tenth after poor tee-shots but Larrazábal once again holed a long putt - this time from 25 feet on the 11th to get the gap back to two.
Long putts were the order of the day and Fox drained a 44-footer on the 12th before a stunning bunker shot ahead on the 13th set up another gain and he had some breathing space with a four-shot lead.
A Larrazábal bogey on the 17th saw him sign for a 69 and he was replaced in second by Fisher, who completed his 66 with a two-putt birdie on the last.
The 2010 Ryder Cup player had also taken advantage of the other three par fives and the short par fours on the front nine, holing lengthy putts on the 11th and 12th and dropping shots on the ninth and 15th.
He was four back as he signed his card but Fox hit stunning second into the last to make a two-putt birdie and seal a five-shot win.
Long was bogey-free as he matched his lowest ever DP World Tour round - posted over this layout last week - with a 64, while Lombard dropped a single shot in a 65.