While the Mets outfield watched, Charlie Blackmon kept running for an inside-the-park homer

In the top of the seventh inning of Colorado's 13-4 win over the Mets on Sunday, Rockies outfielder Charlie Blackmon hit a deep drive to left-center field. The ball hit off a sign just above the left-field wall, causing center fielder Curtis Granderson to assume that the ball was a home run. 
And he was right ... eventually. In fact, the umpiring crew had ruled the ball still in play, and as the ball rolled back toward the infield, Blackmon just kept running and running and running:

By the time Granderson and Jay Bruce realized what had happened, Blackmon had already crossed home plate for what was officially deemed an inside-the-park home run. It's Blackmon's second inside-the-parker of the season. According to Elias, he's the first person to have two in one year since former Rockies player Brandon Barnes back in 2014. Take a look at both below: