It was a showdown worthy of two men who already have spots in the World Golf Hall of Fame.
Langer has 31 career victories and $22 million in earnings on the PGA Tour Champions, trailing only Hale Irwin's 45 wins and $27 million.
Langer pulled ahead of Singh with a 12-foot birdie on the par-4 16th.
Langer shot a final round 4-under 68 to overtake Vijay Singh of Fiji, who entered Sunday's round with a one-stroke lead.
Langer began the third round with a two-shot lead over Singh that held up through the first six holes.
It's the second time in his career Langer has won consecutive senior majors.
Nicklaus never won all five (he never got the Senior British Open), but he did win eight senior majors. The Masters in 1934 was not what it would become, but every player who has won it is recognized as a major victor. I was really exhausted. That tournament didn't become an official major until 2003, according to GolfDigest.
Jack Nicklaus weighed in via Facebook, congratulating Langer on breaking his senior major championship record, but didn't delve into the controversy of Player's pronouncements.
"He played awesome", Langer said of his opponent. "I got up early at 5 a.m. and went through my stretching routine and stuff and then heard about the delay, so sat around for an hour and a half, got all stiff again, so that part didn't help". If he made a few putts he would have had me. Vijay Singh is playing the event for the first time in his fifth year of eligibility and still wants to compete on the PGA Tour. Singh got up and down for birdie, but Langer made his short par putt to win the championship.
Conversely, Langer's putting game shined as he made crucial birdie putts on the ninth, 13th and 16th holes to keep the pressure on Singh in their mano-a-mano duel.
Langer missed seven greens in regulation after missing just three greens the first two days, but he scrambled well, getting up and down all but one time. Langer, unable to reach the green with a driver, hit a hybrid off the tee. "I'm not sure many people have done that".
Much will depend on how the PGA of America decides to set up the Trump Potomic Falls course, a new-built Tom Fazio design that can be played at over 7,600 yards.
Standing just off the green to greet Langer was his daughter, Christina, who flew to the tournament from Seattle to surprise her father and watch him win his 32nd event on the Champions Tour. Langer became the only player to win all five senior majors.