Watch: Mavericks' Derrick Jones Jr. takes over in the second quarter of Game 2

The Celtics went on a 9-0 lead to take a 36-35 lead in the second quarter while holding the Mavericks scoreless for four-and-a-half minutes. Then it was Jones' time.

First, Jones hustled for an offensive rebound off a Josh Green miss, then found Green for a layup with his first assist of the game. Then, Luka Doncic found him for a layup with a spectacular behind-the-back pass.

Jones followed that up with an example of the main reason he's in the starting lineup for Dallas: Defense. He harassed Jayson Tatum into nearly losing the ball in the backcourt, then swiped his save attempt and took it in for an and-one.

While he only finished the first half with seven points and two assists, that's honestly more offensive production than the Mavericks expected from Jones, who helped hold the Celtics to 54 first-half points. But they're going to need him to pose an outside shooting three instead of just scoring at the rim: Boston is ignoring Jones at the perimeter to send extra help on Doncic and Kyrie Irving.

But his alley-oop, which is the first time the Mavs have even attempted the play in the Finals, might make up for his lack of spacing.