Watch: Francisco Alvarez clubs first career walk-off homer, leads Mets past Orioles

Aug. 20 (UPI) -- Francisco Alvarez whipped his bat high in the zone, splintered an inside fastball and sent it to center field for a 421-foot homer, leading the New York Mets past the Baltimore Orioles with his first career walk-off hit.

Alvarez hit the solo shot in the bottom of the ninth inning of the 4-3 victory Monday at Citi Field in Queens. He went 1 for 3 with an RBI, run scored, walk and a strikeout.

"I was thinking; swing the bat and hit the ball," Alvarez told reporters.

Designated hitter J.D. Martine also hit a two-run homer for the Mets. Left fielder Tyrone Taylor hit an RBI single for the Mets' other run.

Martinez gave the Mets a 2-0 lead with his 393-foot shot off Orioles starter Trevor Rogers in the bottom of the first. Taylor added to the lead in the bottom of the fourth.

Orioles second baseman Jackson Holliday plated third baseman Ramon Urias with an RBI ground out in the fifth. The Orioles scored their second run on a balk in the seventh. Urias hit a 432-foot solo homer in the next at-bat, tying the score.

Neither team scored in the eight. Mets pinch hitter Jesse Winker struck out to lead off the bottom of the ninth, bringing Alvarez to the plate for the game's final at-bat.

Orioles relief pitcher Seranthony Dominguez missed the strike zone with his first three pitches to Alvarez. He then tossed in his up-and-inside fastball. Alvarez cracked into the 97.9-mph offering and slowly walked out of the box as he watched the ball sail high into the sky on its way over the outfield fence.

Mets relief pitcher Edwin Diaz did not allow a hit or run in the top of the ninth to earn his fourth win of the season. Starter David Peterson allowed six hits and three runs, including two earned, over seven innings, but was not on record for a decision. Rogers allowed five hits and three runs over 4 2/3 innings, but also was not on record for a decision.

Urias went 2 for 4 with two runs scored and an RBI in the loss. Orioles first baseman Ryan Mountcastle also recorded two hits.

The Mets (65-60) will host the Orioles (73-53) in the second game of the series at 7:10 p.m. EDT Tuesday at Citi Field.