India reached 227 for six at tea on Sunday, extending their lead to 370 runs on Sunday.
During the session, India added 97 runs to their total, thanks to a partnership of 89 runs between Gill (104 off 147) and Axar Patel (45 off 84).
Gill showcased his brilliance with a third Test century, while Axar, batting at number six, displayed confidence in his approach.
Gill, who had reached his half-century before lunch, continued to take on the spinners aggressively. When leg-spinner Rehan Ahmed attempted the round-the-wicket tactic, Gill responded by stepping out to smash him for a straight six. He then unleashed the sweep and on-drive for consecutive fours in the same over.
In the 52nd over, Gill reached his century off Bashir, but his celebration was subdued, perhaps reflecting an expectation of greater consistency from himself. This marked his first 50-plus score in 13 innings.
A tactical move by Ben Stokes, placing a short mid-on and short mid-wicket, led to Gill attempting a reverse sweep off Bashir. But the ball deflected from Gill’s gloves, and keeper Ben Foakes easily caught it.
Gill survived two close DRS calls in successive overs during his knock.
(With PTI inputs)