During Tuesday night's "Subway Series" matchup against the Mets, the Yankees defense made a costly mistake.

In the top of the sixth, the Yankees failed to capitalize on an opportunity to preserve their 2-1 lead. 

As he rounded third, Mets first baseman Pete Alonso stumbled and attempted to get back to the base. 

Despite the Yankees' best efforts to get Jeff McNeil out at second, Alonso took off running for home.

As Alonso crossed the plate, McNeil returned to second base safely, ending the game 2-2.

It was a final inning without any more runs for the Yankees, as the bleeding was stopped there.

Going into the top of the seventh inning, the game is still tied at two runs apiece with two outs to spare.

A sweep or split depends on tonight's game. Game one of the series was won 4-2 by the Yankees.