Chasing 141 to win, opener Dwayne Smith smashed a 47-ball 63 (4x4, 3x6) to steer the chase.
Smith got able support from West Indian mate Kieran Pollard (31 n.o., 20b, 2x4, 3x6) and their 51-run stand for the fourth wicket dashed Lions' hopes of an upset.
However, Sachin Tendulkar once again failed to fire, getting clean bowled by Sohail Tanvir for five.
Earlier, Mumbai Indians' decision to field after winning the toss was proved right as they restricted Highveld Lions to 140 for five in their 20 overs.
The Lions never looked focused and made slow progress, making things easy for the opponents.
The chest-high deliveries by Mitchell Johnson, who opened the bowling for Mumbai Indians, bothered Lions openers Quinton de Kock and Rassie van der Dussen.
The Lions innings did not feature any worthwhile contribution. The team from South Africa was reduced to 3 for 62 before skipper Alviro Petersen stepped in.
Petersen played a crucial cameo and was later joined by Dwaine Pretorius in a bid to revive the innings.
The duo put up 50 runs for the unbeaten sixth wicket. That boosted the score, which was once tottering at 81 for five.
Petersen entertained the crowd, smashing successive sixes off Pragyan Ojha. He literally ploughed a lone furrow as the team crashed to 71 for four.
The skipper showed some spunk but found little support at the other end, till Pretorius came in. A power failure led to a stoppage for 21 minutes.
