The Australian entered the final day at Mount Juliet Estate with a one shot advantage and while he extended that to three in the early stages of his round, he would not have it all his own way.
After losing control off the tee, he had to utilise all his scrambling skills and mental strength to reach the turn in 35 and at that point, he had been caught at the top of the leaderboard.
But the 25-year-old produced a wonderfully composed performance down the stretch, coming home in 33 to finish at 19 under, three shots ahead of Swede Rikard Karlberg and four ahead of American Johannes Veerman.
The victory also gives Herbert a place in the field at The 2021 Open Championship alongside Karlberg, who birdied three of his last four holes in a 67, and Veerman who carded a 71.
He came from six back to win his maiden European Tour title at the 2020 Omega Dubai Desert Classic but had no such trouble in County Kilkenny, becoming the second wire to wire winner on the 2021 Race to Dubai after Bernd Wiesbgerger at the Made in Himmerland presented by FREJA, holding the solo lead after every round.
Herbert had fallen out of the top 200 on the Official World Golf Ranking when he won in Dubai but he will now hit a new career high, sitting just outside the top 50, and he revealed that when he was playing this event in 2019, he was not sure if Tour life as a professional golfer was for him.
"I just really wasn't enjoying my life on the road and I think at the end of that week I was pretty much questioning whether this was the career that I wanted to do," he said. "I'd never played full time on Tour with a full Tour card and been away from home so much as well. I think that was the first case of reality and I don't know that I really enjoyed it that much at the time. There was a lot of soul searching going on.
"The people around me that were the closest, that were looking after me the most, I wasn't treating them the way I probably should have. It was just a big soul search after the following week, The Scottish Open and flew home. I had to do a lot of thinking and that Irish Open was probably the low point. For it to come full circle now and be holding this trophy, it's really special."
He added: "Looking at the names on that trophy, it's pretty special, to add my name to that list is something that nobody can take away from me now and it's very, very satisfying to do it.
"I won in Dubai last year and how much that benefitted me winning the event rather than a top five or a top three. A win is so much more than a second place so I was mentally trying to keep that at the forefront of my mind today - a win is a lot bigger than just a good finish and I was proud to finish the way I did."
Herbert soon turned his one shot lead into a three shot advantage as he holed from 15 feet after taking an iron off the tee at the second and put his tee shot to similar range at the par three third.
Looking at the names on that trophy, it's pretty special, to add my name to that list is something that nobody can take away from me now and it's very very satisfying to do it
A tee shot right into the bushes at the fifth led to a bogey as Veerman got up and down to trim the lead to one and Herbert's troubles off the tee would continue on the seventh and eighth.
He had to play out sideways after going right off the tee on the former, doing brilliantly to get up and down from 179 yards to save par, before he went a long way left off the eighth tee, hit a tree with his second and then again managed to save par with an 18 footer.
He remarkably made the turn in a one under 35 but finally had some company from the flying Francesco Laporta.
The 30-year-old had bogeyed the first but he made the most of the fifth, chipped in at the sixth and then put an approach to 15 feet on the seventh.
A fourth chip in of the week on the eighth followed and he holed from 40 feet on the ninth and then 15 feet on the par five tenth after finding sand off the tee for six birdies in a row.
Herbert was forced to lay up on the par five tenth but holed a 25 footer to reclaim the solo lead, with Veerman also making a gain from the fringe after laying up.
Veerman shared the lead as he holed a 25 footer on the 14th to bring huge cheers from the assembled crowd but Herbert hit back on the next, driving into the greenside bunker and getting up and down.
Another stunning bunker shot on the 16th helped Herbert save par, with Veerman failing to do the same from a plugged lie, and an up and down on the 17th handed the leader a three shot advantage heading up the last.
Veerman then bogeyed the final hole after failing to get up and down and solo second went to the fast finishing Karlberg.
The 34-year-old had birdied the first from six feet and made an up-and-down at the par five fifth but came to life near the end, putting his approach to four feet at the 15th, getting up and down from the rough on the 17th and chipping in on the last.
There was heartbreak for Laporta, who found water at the 18th for a double bogey that ended his Open chances as he finished at 14 under alongside English pair Richard Bland and Dale Whitnell and Scottish duo Grant Forrest and Richie Ramsay.