Rose knew that from experience.
Only a week ago in the Travelers Championship, he took a three-shot lead into the final round and collapsed on the back nine . On Sunday at Aronimink, he was five shots clear going to the back nine and found himself in a battle he didn't expect.
He lost another big lead. This time, he didn't lose the tournament.
Rose hit every green in regulation on the back nine, including the final one, and closed with seven consecutive pars for even-par 70 to win for the second time in three starts on the PGA Tour.
The relief at the Memorial came from winning for the first time in America.
The relief at Aronimink was for learning not to lose.
"I knew having not closed out last week it was important for me - just for myself - to do it today," Rose said after his one-shot victory over hard-charging Ryan Moore. "Still, it's never easy to close these things out, I'll tell you."
He sure made it hard on himself.
Staked to a five-shot lead at the turn after a 5-wood to tap-in range for eagle on the ninth hole, Rose had three-putt bogeys on the 10th and 11th holes - after having gone 274 holes without one on the PGA Tour - and just like that, the game was on.
Moore one-putted his last eight greens, including a 12-foot par putt on the 18th hole, for a Sunday-best 65 to make Rose work to the very end. Rose two-putted up a dangerous ridge on the tough 17th for par. And with the Fourth of July fireworks booming in the distance, he hit the fairway and green for one last par.
"I knew level par would get the job today," Rose said. "Every two-putt felt like hard work coming in, I've got to tell you. It was good fun. "
The consolation prize for Moore, who finished second, was a trip to St. Andrews for the British Open. Rose earned a spot in the British Open through a special money list, along with Travelers winner Bubba Watson, who did not play this week.
Tiger Woods wasn't close at all. The defending champion shot 71, marking the first time in 11 years that he didn't break par over four rounds in a regular PGA Tour event. He wound up 14 shots behind Rose, the most Woods has finished out of the lead since the 2006 Players Championship.