Beth Mooney (56) and Ashleigh Gardner (79*) powered the Giants to 201, while Richa Ghosh (64*) and Kanika Ahuja (30*) guided RCB to a record chase.
Nat Sciver-Brunt's 80* and Harmanpreet Kaur's 42 took MI to 164, but DC edged a last-ball win with Shafali Verma (43) and Niki Prasad (35) leading the charge.
UPW managed 143/9, with Deepti Sharma (28) and Uma Chetry (24) top-scoring, but Ashleigh Gardner's fifty (50) and Harleen Deol's unbeaten 34* secured a Giants' win.
Renuka Singh (3/19) and Georgia Wareham (3/25) shone, while Smriti Mandhana's 81 (53) and Danni Wyatt's 42 (31) sealed RCB's win over DC.
Hayley Matthews' 3-fer (3/24) and Sciver-Brunt's 57 (45) helped MI defend 120 against GG, marking their first win.
Kiran Navgire (51 off 27) and Chinelle Henry (33* off 15) lifted UPW to 166, but Meg Lanning's 69 (49) and Annabel Sutherland's 41* (35) guided DC to victory.
The action now shifts to Bengaluru, where the next leg begins on February 21, featuring hosts RCB taking on MI.