The German bear American duo Kevin Sutherland and Woody Austin in a play-off to claim his fourth Champions Tour victory this season and 29th overall since turning 50.
“I blew tournaments when I had a lead and I’ve come from seven behind, so you just never know,” said Langer after holing a three-foot birdie putt on the first hole in the play-off to claim a second success in the event.
A day after his 59th birthday, Langer birdied the par-5 18th in regulation for a five-under 67 to match Austin (67) and Sutherland (64) on 13-under 203 at TPC Snoqualmie Ridge.
Colin Montgomerie closed with a 68 - nine shots better than his opening effort - to finish joint-55th.
First-round leader Ross Drummond finished joint-third behind Englishman Gary Marks in the inaugural Willow Senior Golf Classic at Hanbury Manor.
Marks, who’d shot a 63 in the second round, secured his first European Senior Tour title in just his 17th event with a two-shot victory over South African James Kingston.
Drummond finished a shot further back after a closing 70 to earn £18,300.
Euan McIntosh celebrated his Scottish Order of Merit title triumph in style by coasting to an eight-shot victory in the South East District Open at Royal Musselburgh.
The 47-year-old Turnhouse player carded rounds of 70, 63, 67 and 64 for a 16-under-par total to finish well clear of defending champion Matt Clark (Kilmacolm) in second place.
McIntosh, a reinstated amateur, has made an incredible return to the domestic scene since deciding to make a comeback just over a year ago.
He secured a Scotland return after a 27-year gap in the Home Internationals at Nairn earlier this month and recorded eight top-10 finishes in 10 counting events in the Scottish Order of Merit.
Catriona Matthew finished in a tie for 37th as world No 2 Ariya Jutanugarn coasted to a four-shot win in the Canadian Pacific Women’s Open in Calgary.
Matthew closed with a 71 for a two-under-par 282 total to earn $11,880.
Jutanugarn as she shot a six-under-par 66 to finish on 23-under, four shots clear of South Korean Sei Young Kim.
It was Jutanugarn’s fifth win of the season.
Graham Fox (Clydeway Golf) and Jason McCreadie (Largs) shared the spoils in the Tartan Tour’s Kerr Investments Pro-Am at Dumfries & Galloway.
The duo shot matching rounds of 65 and 63 in the Order of Merit event for 12-under-par totals, finishing one ahead of Greig Hutcheon (Paul Lawrie Golf Centre Inchmarlo).
Fresh from winning the Scottish Young Pros Championship for a third time in four years, Paul O’Hara (North Lanarkshire Leisure) finished fourth on 131.