After winning the match by 5 wickets, Islamabad United will now face Lahore Qalandars in the second eliminator of the league.
Harris was the second player to be dismissed for 70 off 32 balls with five sixes and seven fours.
On this occasion, Harry Brook and David Wise took the team and formed a good partnership to take the score to 149 runs.
The duo put up a 92-run partnership off 52 balls, which helped Islamabad United to a 229-run stand for the loss of four wickets.
The Sultans had not yet recovered from the loss as they suffered a third run as a result of another run out.
Alex Hales hit an unbeaten 82 off 54 balls with 13 fours and a six while Rahmanullah scored 27 off 16 balls.
The two had been at the forefront of their teams’ successes.