Electing to field, Mumbai produced a fine bowling display to restrict the Lions to 140 for five and then rode on Dwayne Smith's unbeaten 63 to chase down the target with nine balls to spare.
"There was something in the wicket and we used it to our conditions. Credit to the bowlers who restricted a good batting line up," Rohit said at the post-match presentation ceremony.
Lions' skipper Alviro Petersen said they were 20 runs short of what could have been a winning total.
"We were looking at 160, we looked good to get it early on, but lost our way," he said.
More From This Section
"It wasn't quite like the Wanderers here, because it was a touch slow, but it was a brilliant wicket."
Man-of-the-match Smith said his game plan today was just to spend time at the wicket.
"I can change my game, especially when we are losing wickets, and it's up to me to be smart and do that. I just have to be confident," Smith added.