Tony Finau produced a terrific Sunday performance to win the 3M Open with a final score of 17 under par – even if It was not quite a comfortable finish.

The American completed his final round with six birdies and two bogeys to post the equal second-best score of the day with a 67. One bogey came on the 18th after Finau teed off into the water, but he was never in any real danger after starting that hole with a four-stroke lead.

Finau's charge to the front of the field began during his back nine, when he rattled off four birdies over the course of six holes – including three in a row on 14, 15 and 16 – perfectly coinciding with the collapse of 54-hole leader Scott Piercy.

Speaking to CBS after stepping off the 18th green, Finau said it felt like he was a long way off the lead until it all started to shift.

"[It took] really everything I had," he said. "I was playing great, and every time I looked it up it seemed like I was four or five shots back, really all day.

"I really got things going down the back nine, and once I took control of the golf tournament it was a totally different mindset, trying to seal the deal.

"It's so special just to have my family here with me, and to celebrate this win with them… this one was for them."

Piercy began his day at 18 under with a four-stroke lead, and he was cruising early, making a couple of early birdies to jump out to 20 under, with his buffer extending to five. But everything began to fall apart on the eighth hole.

After back-to-back bogeys on eight and nine, Piercy also bogeyed 11, teased a bounce-back with a birdie on 12, and then capitulated with bogey, triple-bogey, bogey from his next three holes to go tumbling down the leaderboard. Over the course of eight holes, he dropped seven shots, completely eliminating himself from contention.

Piercy finished tied for fourth at 13 under after his 76, along with fellow Americans Tom Hoge and James Hahn, with Hahn's six-under 65 ending up two strokes better than any other final round.

That grouping was one stroke behind Argentina's Emiliano Grillo and South Korea Im Sung-jae, who were tied for second at 14 under.

Rounding out the top 10 were the English pairing of Danny Willett and Callum Tarren, tied for seventh at 10 under along with Greyson Sigg, with Chesson Hadley one shot back.

Recent PGA Tour winner J.T. Poston headlined the group at eight under, and Australia's Cam Davis was at seven under as he prepares to defend his Rocket Mortgage Classic crown this coming week.

Scott Piercy holds a commanding four-stroke lead coming into the final round of the 3M Open, after posting a five-under 66 at TPC Twin Cities.

Coming into moving day with a three-shot lead, Piercy was red-hot on the front nine on a rain-interrupted Saturday in Blaine, Minnesota, scoring five consecutive birdies between holes three and seven.

A bogey on the par-five 18th to close out the round put him on 18-under after 54 holes, moving him four shots clear of Emiliano Grillo in second.

Piercy's last win on the PGA Tour came alongside Billy Horschel as the 2018 Zurich Classic, with his last solo win on the tour going back three years further, taking out the 2015 Barbasol Championship.

Grillo's last win on the PGA Tour also came in 2015, winning the Frys.com Open in a playoff, and he's in contention despite an up-and-down third round amid suitable conditions.

Afternoon thunderstorms caused the third round to be moved up, and without much, the more accessible pin locations and shortened course distance made for low scores.

Grillo and Im Sung-jae were the only players to finish Saturday in the leaderboard's top ten with a third-round score of less than five-under.

Going four-under over the opening six holes after an eagle on the par-five sixth, the Argentine also had to birdie the last to make up for bogeys on the ninth and 15th holes.

Doug Ghim and Tom Hoge are a further stroke back on 13-under, with both posting scores of six-under 65 for their third rounds.

After three consecutive birdies between five and seven, Finau made an extraordinary par save on the par-four ninth, after failing to make the green with his opening three shots.

With the ball nestled in the rough just off the green, the 32-year-old turned his putter sideways and after a couple of practice strokes, made a 34-foot save with the putter's toe.

Scott Piercy's putter was on fire for the second round in a row, setting up a seven-under 64 to follow his opening 65, and at 13 under he is three strokes clear of the chasing field.

Piercy – who this week changed his coach, swing, caddie, driver and putter – seems to be reaping the benefits of his bold moves, going bogey-free on Friday in a round that included four consecutive birdies to open his round on the back-nine.

He trailed only first-round co-leader Im Sung-jae in strokes gained with the putter on Thursday, and he was again second in that category in his second trip around the course, finishing with 3.96 strokes gained on the greens. Only Danny Willett (5.46 strokes gained) performed better with the flat stick.

In outright second place at 10 under is Argentina's Emiliano Grillo, with a strong 65 that included an eagle. He did not excel in any one area in his first round, but on Friday he was top-10 in both strokes gained putting (3.12 strokes, seventh-best) and in approach shots (2.57, ninth-best).

Grillo is two strokes ahead of England's Callum Taren, who is alone in third place at eight under, and he worked his way there after an even-par opening round. 

He shot Friday's round of the day with his eight-under 63, going bogey-free with eight birdies, finishing fifth on the day in strokes gained putting (3.36), second in strokes gained off the tee (2.07) and second in strokes gained tee-to-green (4.92).

There is a five-way tie for fourth at seven under, with American quartet Tony Finau, Robert Streb, Tom Hoge and Doug Ghim, as well as Im after the South Korean followed his six-under opening round with a disappointing 70.

The group tied for ninth are a further two strokes back at five under, which includes Patton Kizzire and Jared Wolfe, while Australia's Cam Davis and England's Willett headlining the group at four under.

Canada's Adam Hadwin finished right on the cut-line at one over, while Davis Riley missed out on the weekend by one stroke, with Beau Hossler at three over and Cameron Tringale at four over.

Russell Henley carded his first bogey of the tournament but still managed to double his lead at the Wyndham Championship on Friday. 

Seeking his first PGA Tour win in four years, Henley shot 64 in the second round and sits at 14 under par for the tournament. 

That left him four strokes up on Rory Sabbatini (64), Webb Simpson (65) and Scott Piercy (66) heading into the weekend in Greensboro, North Carolina. 

Starting on the back nine at the Sedgefield Country Club, Henley bogeyed number 12, his third hole of the day, before reeling off four consecutive birdies from 14 through 17.

Three more birdies coming home after the turn solidified his edge as he eyes his first win since the 2017 Houston Open. 

Henley's 126 matches the lowest 36-hole score posted on tour this season along with Stewart Cink at the RBC Heritage. 

Tokyo Olympics silver medallist Sabbatini had a bogey-free day to match Henley's round, while Simpson remained near the top of the leaderboard thanks in part to an eagle at the fifth. 

Simpson's success is no surprise, as he has finished in the top three at the Wyndham the last four years after winning it in 2011. 

Tyler Duncan had the best round of the day with a 62 that left him five shots back at nine under along with Justin Rose (65) and Brian Stuard (66). 

Among other notables, Bubba Watson (69) and Adam Scott are 10 strokes back at four under, one shot better than the cut line. 

Masters champion Hideki Matsuyama (69) missed the cut by a stroke, while former world number one Luke Donald (67) finished at one under and two-time major winner Zach Johnson fell short at even par along with defending tournament champion Jim Herman. 

Also finished for the week-end are Padraig Harrington (76) at two over, Rickie Fowler (72) at three over and Charl Schwartzel (73) at seven over. 

Fowler's missed cut means his season is over, as he will not make the FedEx Cup playoffs for the first time in his career. 

Two players who were tied for second after Thursday's opening round, Michael Thompson and Ted Potter Jr., also missed the cut after slumping to 74 and 77, respectively.