It wasn’t that long ago that Justin Rose, the world’s ninth-ranked golfer, thought it might be impossible to win on the PGA Tour.

Perhaps he shouldn’t have been that concerned.

Two weeks ago, Rose tied for second at the Masters with a 14-under-par score that would’ve won the green jacket in almost any other year. He came to the Zurich Classic of New Orleans this week with renewed optimism.

Rose left Sunday afternoon, after more than 9½ hours of weather delays over a four-day span, with his seventh PGA Tour victory following a dramatic birdie-birdie finish.

“I was struggling with my game, and when you’re struggling with your game, sometimes winning seems very far off,” Rose said of his play earlier this year. “So I’m very happy to have turned my game around the last three or four weeks.”

The twin birdies capped an amazing string of 66 consecutive bogey-free holes at the rain-softened TPC Louisiana layout, helping Rose close the tournament with a 6-under 66 and course-record 266 total. That topped the course mark of 268 set by Billy Horschel in 2013.

Since the field wasn’t re-paired at the end of the rain-delayed third round late Sunday morning, Rose, who shared the 54-hole lead with Jason Day at 16-under, had to wait 45 minutes to officially claim the win and collect the $1.242 million first prize from the $6.9 million purse.

Rose won by a stroke over Cameron Tringale, who closed with a 65 for a 21-under 267 total, and by two over first-round co-leader Boo Weekley, who also shot 65 on Sunday to finish at 20-under.

Day, who fired a 65 in the second round and a 68 in the third round, shot a 69 on Sunday, when scores generally plummeted because of rain-softened greens. Players also benefited with the lift, clean and place rule in effect, yielding a scoring average of 69.113 — the lowest of the tournament.

While Rose didn’t have the low round of the day, he finished with a flourish nonetheless.

As he went about his business with three birdies on the front nine, an ever-changing leader board had Tringale, Blayne Barber and Jim Herman taking turns at the top when the last five threesomes moved to the back nine.

Tringale looked like he wanted to take the title with five birdies on the front nine and another at No. 11 before he dropped a stroke at the par-4 13th and fell into a tie with Rose.

Rose went to the difficult par-3, 213-yard 17th hole figuring he needed to make something happen, and he did.

With the pin tucked on the left side of the green, perilously close to the pond that lines the hole, Rose pulled out his 5-iron and put the ball just 10 feet from a birdie — which he sank — after missing a birdie opportunity at No. 16.

“Walking to 17, I knew I needed to be looking at the flag there,” he said. “I had a great number at 213 (yards), so it was a very comfortable yardage for me to be aggressive.”

A few minutes later, he faced another birdie putt of 13½ feet at No. 18 and rolled that in — punctuating it with a yell and fist pump.

Rose, who has shot par or better in his past 16 competitive rounds at TPC Louisiana, said he’ll remember the putt on No. 18 more.

“Whenever you hole a putt on the 72nd hole to finish out a tournament, you know, those are the most meaningful putts,” he said. “The putt at 17 sets up the opportunity to win the tournament. But when you go ahead and slam the door by making a nice putt like that (at No. 18) … that’s far and away the best feeling.”

After watching Tringale and the players in the other four groups come in, Rose finally was able to celebrate.

“Obviously, when you get down the stretch, all of us out there are competitors,” he said. “So yeah, to finish strong like that was just … that’s the thing I’ll be most proud of when I look back on this tournament.

“It’s not necessarily the bogey-free run or the 22-under-par. It’s knowing that I needed to do something walking up to the 17th tee and pulling it off.”

Follow Sheldon Mickles on Twitter @MicklesAdvocate.