Lingmerth won for the first time on the PGA Tour after a par on the third sudden death hole was enough to beat 2013 U.S. Open champion and world number six Rose, with 18-time major champion and tournament host Jack Nicklaus looking on.
Tiger Woods shot a two-over 74, an 11-shot improvement on his career worst 85 on Saturday. The 39-year-old finished last at 14-over 302, the worst 72-hole total of his career.
For Lingmerth, the victory will live long in the memory.
“This is my third year on the PGA Tour, and it's one thing to be a PGA Tour player, but it's a whole other thing to be a winner out here,” he said.
“Just to be on that list of PGA Tour winners is a special feeling and something that no one can take away from me.
“And this tournament, with Mr. Nicklaus as host, I can't think of many other tournaments that would be put above this one so I'm pretty thrilled.”
Playing in the event instead of his home country's flagship event, the Swedish Masters, the 27-year-old shot a final round three-under 69 to finish at 15-under 273.
While the victory gives Lingmerth a three-year U.S. tour exemption and entry to the PGA Championship and next year's Masters, he still faces a 36-hole qualifier for the US Open on Monday.
The qualifier in Columbus for a place at the June 18-21 US Open at Chambers Bay is one of the main reasons he chose to play the event.
“It is a little heartbreaking not to get to play in Sweden but sometimes you have to make those decisions,” he said.
“And this year I'm definitely happy I made this one.”
England's Rose, the 2010 Memorial champion, led by three overnight but trailed by the same margin through eight holes after a rough start. He was forced to make par on the final hole after hitting a spectator in the head with his approach, posting a 72 to set up the playoff.
“I take confidence, really. I think for the most part I played well this week,” said Rose.
“I feel like I have another gear.”
World number two and Masters champion Jordan Spieth shot a 65 to post the early clubhouse lead but eventually tied for third with Italian Francesco Molinari (71) at 13-under.
Molinari had a two-shot lead at the halfway point of the final round and a share of it through 15 holes before dunking his tee shot into water on the par three 16th.
The resulting double bogey was enough to drop him out of contention.
Australian Marc Leishman (69), veteran American Jim Furyk (71) and defending champion Hideki Matsuyama (70) of Japan shared fifth place at 12-under. – Reuters
Original source: Lingmerth wins Memorial after play-off