With the tie level at 2-2 on aggregate, the game went into extra-time. Both teams had chances to score, but it was Ballard who ultimately made the difference with his late goal.
Coventry fought hard to get back into the game after falling behind in the first leg, but ultimately fell short against a determined Sunderland side.
Now, Sunderland will face Sheffield United in the Championship play-off final at Wembley, with a spot in the Premier League on the line. It promises to be an exciting and dramatic match for both teams and their fans.