Arshdeep Singh returns to the attack, and Dube nudges one down to fine leg for a single. Sarfaraz Khan then takes charge, smashing back-to-back boundaries and then a third!
The Mumbai-born CSK duo are lighting up Chepauk, thrilling the home crowd.
Earlier in the innings, another Mumbai batter had produced a hat-trick of boundaries, and Sarfaraz is following suit.
He drives the next delivery to sweeper cover for a single, and Dube flicks one to midwicket for another single.
15 runs come off the over, taking CSK to 145 for 4 after 15 overs.