The achievement marks Slot’s first piece of silverware since succeeding Jürgen Klopp.
Tottenham went into Thursday’s match with a one-goal advantage after they beat Liverpool in the first-leg tie at the Tottenham Stadium.
Liverpool remain top of the table after Chelsea’s goalless draw at Everton.
Manchester City’s misery continued with a shock 4-0 Premier League rout by Tottenham Hotspur at Etihad Stadium on Saturday.
United have lost three matches and drawn one game this season.
Tottenham manager Ange Postecoglou dismissed suggestions that Spurs fans might prefer their team to lose to prevent arch-rivals Arsenal from winning the title.
With a 3-3 draw, City have now gone three games without a win.
The four-goal thriller game ended 2-2 with both teams sharing points at the Emirates.
With Saturday’s results, City maintained the top spot on the EPL logs with a maximum of 15 points in five games.
“It was frustrating when we missed the penalty. We were playing well, and we didn’t get the reward.”
