A heckler crossed the line during the Diamondbacks game Tuesday night -- making a comment to Ketel Marte that was so insensitive, it actually reduced the baseball star to tears.
The emotional scene unfolded late in Arizona's tilt vs. the White Sox ... after a fan had made a remark to Marte around the time he popped out to end the top half of the seventh inning.
The Snakes second baseman was seen on the game's broadcast being consoled by his teammates and coaches in the middle of Guaranteed Rate Field's infield .