Dwayne Smith spectacularly finished what Sachin Tendulkar started as Mumbai strengthened their claims to a place in the Indian Premier League knockout stages with a thrilling last-ball victory over Chennai.
The Indians' chances of chasing the Super Kings' 173-8 seemed to have gone when they lost seven wickets for 25 runs, following a century stand between Tendulkar (74) and Rohit Sharma (60).
But that was reckoning without Barbados all-rounder Smith, who first of all kept his cool while four other batsmen were making ducks around him.
It still appeared Mumbai had run out of steam until Smith hit the last three balls of the final over, from Ben Hilfenhaus, for a six and two fours to finish with an unbeaten 24 and sneak a highly-improbable two-wicket win.
Lasith Malinga (3-25) and RP Singh (3-28) had earlier been responsible for six of the CSK wickets but opener Murali Vijay (41) and West Indies all-rounder Dwayne Bravo (40) ensured a challenging total.