PORT ST. LUCIE, Fla. -- Before emerging from a corridor into the Mets' press conference room Saturday at First Data Field, Pete Alonso paused to watch video of his home run on a team staffer's phone. He had not yet seen footage of the line-drive, two-run shot he clubbed in the Mets' 4-3 victory over the Braves, on the first pitch he saw this spring. Once his private viewing session ended, Alonso stepped into the room wearing a wide grin.

"I love moments [like that]," Alonso said. "I love being challenged. That's one of the things I take pride in is stepping up and not backing away from a challenge."

This spring, Alonso's challenge is plain to see. A year after bashing 36 home runs in the Minors, the club's No. 1 prospect per MLB Pipeline is in big league camp attempting to win the Mets' starting first-base job. His opponents include Dominic Smith, another former top prospect who has struggled in the big leagues; and Todd Frazier, last year's starting third baseman whom the Mets displaced from that position.

Both have their merits. Neither has the momentum of Alonso, whom the Mets insist they will carry north if he proves he's one of the 25 best players in camp.

"I just want to play the best I can consistently," Alonso said. "I just want to be the best I can be and I want to be the guy on the Opening Day roster. There are other people who want that job, too. I just need to keep working hard and play well, simple as that. It's Game 1. Hopefully I can continue to play well throughout these five weeks we have left in spring."

If nothing else, he's off to a blistering start. Batting sixth in the Mets' Grapefruit League opener, Alonso stepped to the plate with a man on first base and one out in the second inning, extending his arms on a Touki Toussaint fastball. He pulled the ball away from the strike zone's outer third, yanking it just to the left of the towering batter's eye in center field.

"That's probably the hardest [hit] ball I've given up," Toussaint said. "I've seen him hit some balls, but that one was impressive."

Watching from the bullpen, pitcher Hector Santiago saw the swing and heard the crack of the bat, and whipped his neck around to watch the ball's flight over a pair of television cameras perched above the wall.

"I was like, 'He got a hold of that one,'" Santiago said. "Then it went over the camera guy and I was like, 'Whoa, he really got a hold of that one.' Effortless. He's very strong."

What Alonso is not, however, is a finished product. When the Mets decided not to call him up last September, they cited his defense as a significant reason. Pegged well below average at first base by most scouts, Alonso has made it his mission to improve, working privately with infield coordinator Tim Teufel on the back fields this spring. Saturday morning while his teammates took batting practice, Alonso again put his work in at first, scooping ground balls and flipping them to a coach.

The extra reps did not pay immediate dividends; in the second inning, Alonso dropped a high-velocity throw across the diamond by Amed Rosario, saying afterward that there is "no excuse" for the mistake.

"The game seemed a little fast," Alonso said. "It's the first live game. It's been a while. But I felt good."

One game won't do much to change the Mets' perception of Alonso, for better or for worse, though manager Mickey Callaway lauded the rookie's ability to bounce back from his defensive mistake. How Alonso progresses over the next few weeks will have a greater impact on his immediate future.

In the interim, Alonso will stay positive -- something that seems to come naturally. Some insight into his personality: When asked Saturday why he changed his name on all published materials from Peter to Pete, Alonso said it was simply because he liked the more casual feel.

"I think I'm very approachable and I think I'm a nice guy," Alonso said. "Anyone can call me Pete. It's more just an informal thing. If someone calls me Peter it's like, 'All right, you can relax a little bit.'"