This is the difference between really good NBA teams and those fighting just to be mediocre.
The Mavericks - who admittedly have some traveling to do to get mediocre on the radar - had the Boston Celtics down by 13 points with just over seven minutes to play Monday night.
Those would be the Celtics who own the NBA's best record and winners of 15 in a row coming into this game.
Within a blink, the visitors stormed back behind Kyrie Irving, found a way to get to overtime and took charge in the extra frame for a 110-102 victory, dishing out a heartbreaking loss to the Mavericks, who fell to 3-15.