WATCH: Colorado Rockies’ Trevor Story nails a walk-off homer for a sweep

DENVER, CO - JULY 15: Trevor Story #27 and Gerardo Parra #8 of the Colorado Rockies celebrate a ninth-inning, walk-off home run by Story over the Seattle Mariners, as he gives a TV interview to Taylor McGregor at Coors Field on July 15, 2018 in Denver, Colorado. The Rockies won 4-3. (Photo by Dustin Bradford/Getty Images)
DENVER, CO - JULY 15: Trevor Story #27 and Gerardo Parra #8 of the Colorado Rockies celebrate a ninth-inning, walk-off home run by Story over the Seattle Mariners, as he gives a TV interview to Taylor McGregor at Coors Field on July 15, 2018 in Denver, Colorado. The Rockies won 4-3. (Photo by Dustin Bradford/Getty Images)

DENVER – The Colorado Rockies have now won 13 of their last 16 games behind a 4-3 win on Sunday to sweep the Seattle Mariners.

In a tight, back and forth game that was plagued by rain throughout, the Rockies battled from behind twice to tie it. That led All-Star Trevor Story to an at-bat in the ninth against Nick Vincent.

The Colorado shortstop will be making his first appearance at a midsummer classic on Tuesday. But before he got to D.C., he did something he’s never done in his baseball career at any level including tee-ball.

Story took a flat-fastball and drove it 434 feet to dead center.

“That was a cutter that didn’t get away from Trev and he left it up over the plate,” Bud Black said. “Trev squared it up… great swing.”

Trevor Story is now slashing .292/.354/.552 on the year with 20 HRs and 68 RBI. His unbelievable first half has seen him become one of the best hitters in baseball the past six weeks, which only moonlights his Gold Glove caliber defense.

“I knew I was leading off and I saw (Nick) Vincent warming up and I wasn’t trying to do too much,” Story said. “Then I saw a few more pitches and I felt more comfortable.”“It was incredible that’s the first time I hit a walk-off home run.”

For two-straight seasons, the Rockies have finished their first half on a high. Last year it, was Kyle Freeland tossing 8 1/3 innings of no-hit ball at Coors Field against the Chicago White Sox before allowing a single to left field by Melky Cabrera on his 126th pitch of the afternoon in the Rockies’ 10-0 win.

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This afternoon, it was Story with a solo shot to keep the club’s hot stretch hot heading into the All-Star break.

The Rockies are two games back of a playoff spot both in the division and in the Wildcard.

The second half will be a fight between L.A., Arizona and Colorado for the division and possibly a Wildcard spot.

The walkoff also improves the Rockies record in the month of July to 10-3. The Rockies are also averaging more than six runs a game in July compared to allowing just 2.77 runs per game.

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Story will be joined by two other teammates: third baseman Nolan Arenado and center fielder Charlie Blackmon at the All-Star game this week in Washington, D.C..