Matt Kemp -- inspiring chants of "M!V!P!" -- left Harper and his teammates feeling a Dodgers shade of blue with his booming, 10th-inning walk-off homer against Tom Gorzelanny for a 4-3 decision. The Dodgers had been down to their last strike in the ninth against Henry Rodriguez before rallying to seize from the 14-7 Nats the National League's best record at 15-6.
"Seeing him hit a bomb -- that's terrible," Harper said of Kemp. "I wish we'd have gotten that W. Great player, great hitter. If I had a No. 1 pick, he'd be it. Unbelievable player."
In time, Harper might find himself in Kemp's elite company. But he understands he's just getting started, "trying not to be overwhelmed" by the magnitude of it all.
By the time his memorable if ultimately disheartening debut was over, Harper had put on display all of his celebrated wares.
His line-drive sacrifice fly in the top of the ninth against reliever Javy Guerra for the go-ahead run could have made a hero of Harper. Handed a two-run lead, Rodriguez -- his triple-digit heat harder for Wilson Ramos to catch than it was to hit -- was unable to slam the door in the home half, leaving it to Kemp to serve as the closer.
After crushing a double for his first big league hit in his third plate appearance in the seventh, Harper charged A.J. Ellis' two-out single with two on and unleashed a perfect strike home from left field.
It would have been the last out of the seventh inning, preserving Stephen Strasburg's shutout bid, if Ramos had maintained control of the ball. But the catcher's bobble allowed Jerry Hairston to score the tying run.
Washington manager Davey Johnson contested the ruling by home-plate umpire Mark Carlson. Hairston's slide was wide of the plate and his attempted hand swipe missed the mark, but he scrambled back to touch the plate when he saw the ball free.
Johnson by that point already had seen enough from Harper to justify his belief that this 19-year-old phenom has all the skills to go with his drive.
In that first at-bat, long before all the game-changing events, Harper -- the Majors' No. 2 prospect -- grounded sharply back to the mound. It's what Harper did after the ball landed in Billingsley's glove that was impressive.
Even though he was an easy out, Harper dropped his head, sprinted to first and ran through the bag.
"I really had that fire and passion back in my game," Harper said, confessing that it wasn't easy to find it in the 25-degree weather at Triple-A Syracuse. "Coming here, playing with a winning team like we are, it's a great opportunity to play and have that passion back."
It is Harper's burning ambition as much as his power, speed and arm that has Johnson singing his praises.
"Bryce is so driven," Johnson said, "a lot of times he tries to do too much. He's much more driven than anyone I've seen. He wants to be a very good player. Now he can get started."
After flying to left in his second at-bat, Harper followed Adam LaRoche's homer, which gave Strasburg a lead, with his two-out double to dead center.
Taking the count full, Harper uncoiled on a fastball and hammered it over the head of Kemp, the 2011 Rawlings Gold Glove center fielder.
Demonstrating his plus speed as the ball rolled to the wall, Harper had a shot at a triple but decided to pull up at second.
"When I hit a ball like that," Harper said, "I'm always thinking three. Everyone in our organization hustles."
With runners at the corners, Harper lashed Guerra's first pitch in the ninth deep enough the other way to cash in Rick Ankiel. Ramos' RBI single gave the Nationals the two-run cushion they were unable to protect.
"He's just a gifted athlete," Johnson said of Harper. "I like everything about the way he plays the game. He plays hard. Old school."
From a baseball lifer such as Johnson, who excelled for 13 years as a second baseman and managed the legendary 1986 Mets to a World Series title, "old school" is the highest of compliments.
While there's nothing old school about his Mohawk-styled hair, Harper, who won't be 20 until Oct. 16, was the only Nationals position player showing stockings with his pant legs rolled up to his knees.
How old school is Harper? He chose No. 34 because "I always loved Mickey Mantle -- and three and four equals seven."
The natural from Las Vegas seemed almost surprised before the game that he wasn't more anxious, that his nerves were so under control. He mentioned "trying to stay as mellow as I can" after Johnson had counseled him to "relax and have fun" in his debut.
"I really didn't have butterflies at all," Harper said. "I'm waiting for it to sink in and feel it. In the dugout before the game, I'm sitting there thinking, `I'm in the big leagues.'"
As "The Natural" from Vegas carries out his journey, he'll never forget the first game.