India suffered a dramatic late collapse as England fought back after an audacious 96 from teenage debutant Shafali Verma lit up the second day of the one-off Test in Bristol.
The tourists had been cruising at 167-0 before Verma was caught chasing the boundary that would have brought her a century.
From then, India folded, losing 5-16 to end the day on 187-5, trailing the hosts by 209 runs.
England had earlier declared on 396-9, led by an unbeaten 74 from Sophia Dunkley.
Verma, 17, hit 13 fours and two sixes as she produced the highest score by an Indian woman on Test debut to frustrate England's bowlers.
She and fellow opener Smriti Mandhana, who made a classy 76, looked to have batted England out of contention but after Verma had hoisted Kate Cross to mid-on, the match swung in the hosts' favour.
India looked scrambled, with skipper Heather Knight taking 2-1 off six overs to put England in prime position in this Test which has two days left to run.
Momentum shifts after Shafali show
Despite having never played a Test together - Verma was just 10 when India last played a red-ball match - the India openers combined gloriously in Bristol.
Verma, the top-ranked T20 batter in the world, played the way she knows how: hard. A seaming delivery from Nat Sciver was flayed effortlessly for six, while premier bowler Katherine Brunt saw a full delivery clattered back over her head.
Accompanied by Mandhana, a classical player with a stunning cover drive, she flayed England's attack around the ground. Verma celebrated her half-century with an abashed wave of the bat, preferring to let her shot-making tell the story.
Her only emotion came when she toe-ended Cross to mid-on, with the opener throwing back her head in anguish as she left.
"This partnership could be huge for women's cricket in India," said former India seamer Snehal Pradhan on Test Match Special.
"I've already seen a lot of people on my social media who don't normally talk about women's cricket, calling for others to turn on the television to watch these two wonderful players."
England were visibly lifted by Verma's dismissal. Mandhana began to struggle to rotate the strike before lofting Sciver to mid-off, Shikha Pandey chipped a catch back to Knight while captain Mithali Raj was pinned lbw on review by Sophie Ecclestone.
The fielders crowded around the bat and turned up the noise as Poonam Raut fell lbw. England almost claimed another wicket, with Harmanpreet Kaur given out lbw to Ecclestone, but a review showed a clear inside edge.
It was a frenetic end to another absorbing day's play.
Dunkley stars alongside Shrubsole fireworks
England put themselves in a strong position with the bat, led by Dunkley, who showed real maturity on her Test debut.
After losing Katherine Brunt to the second over of the day, Dunkley shared a 56-run partnership with Sophie Ecclestone as she moved England beyond the 300 mark.
She was dropped by Deepti Sharma in her follow-through on 27 and then given out on 46, lbw to Sneh Rana, but the decision was overturned on review, before a glance down to fine leg took her to an assured half-century.
Dunkley's off-side game was particularly strong as she struck nine fours, and her partnership with Anya Shrubsole helped England accelerate towards a declaration.
The pair smacked 70 runs in 10 overs, Shrubsole striking a towering six over long-on, before Heather Knight waved her players in after Shrubsole was bowled by Rana.
It was a flurry that epitomised England's positive mindset, but one that was almost instantly matched by Verma and Mandhana's controlled and calculated counter-attack.
