Watch: Diamondbacks' Pavin Smith beats Giants with first career walk-off homer

June 4 (UPI) -- Pinch hitter Pavin Smith smoked a 1-0 fastball to dead center field for a 424-foot, two-run homer, leading the Arizona Diamondbacks to a narrow 4-2 triumph with the first walk-off blast of his life.

The 105.7-mph shot came in the bottom of the ninth inning of the victory Monday at Chase Field in Phoenix.

"Some stuff, you sort of dream of, Smith told reporters. "You play it in your mind. I mean, almost every day, if that situation comes up, you want to be able to do that."

Smith, 28, hit just 29 home runs through his first 323 games. The fifth-year utility man is hitting .255 with two home runs and 13 RBIs through 23 appearances this season. He told reporters that Monday's blast was the first walk-off homer he has hit at any level of baseball.

Diamondbacks starter Ryne Nelson, who allowed just six hits and two runs over 7 2/3 innings, didn't allow a base runner until the fourth.

The Diamondbacks offense woke up in the second, with left fielder Lourdes Gurriel Jr. leading off the bottom of the inning with a 384-foot solo homer. Third baseman Eugenio Suarez followed with a triple two at-bats later. He later scored on an RBI single from shortstop Blaze Alexander.

The Diamondbacks only managed to supply one baserunner over the next four innings and didn't score again until Smith's walk-off.

The Giants cut the deficit in half on an RBI double from third baseman Matt Chapman in the top of the fourth. Right fielder Heliot Ramos tied the game with a 420-foot solo shot off Nelson in the top of the seventh.

Relief pitcher Ryan Thompson entered the game in the top of the eighth. He allowed two hits and no runs over the final 1 1/3 innings to silence the Giants.

The Diamondbacks earned two baserunners in the seventh, but could not plate a go-ahead score. Right fielder Jake McCarthy doubled in the second at-bat in the bottom of the ninth. Smith then settled in against relief pitcher Randy Rodriguez. The right-handed pitcher started the exchange with a fastball outside the zone for a ball. He then heaved in another heater, placing it right down the middle.

Smith jumped all over that pitch, belting it deep to center and winning the game in dramatic fashion.

The Diamondbacks (28-32) will host the Giants (29-32) again at 9:40 p.m. EDT Tuesday at Chase Field. The series finale will be Wednesday in Phoenix.