India overwhelmed England by 157 runs to win the fourth Test at the Oval on Monday and take a 2-1 lead in the five-match series.
England set 368 to win, were bowled out for 210 after tea on the last day with fast bowler Umesh Yadav taking 3-60.
The hosts were relatively well-placed at 141-2 before left-arm spinner Ravindra Jadeja and paceman Jasprit Bumrah both struck twice as England lost four wickets for six runs in 36 balls after lunch.
Star batsman Root, bidding for a fourth hundred in successive Tests, then played on to Thakur for 36 to the delight of India fans among a capacity crowd revelling in the south London sunshine.
And on the stroke of tea, Chris Woakes chipped Umesh Yadav to short midwicket, leaving England 193-8 and India just two wickets away from going 2-1 up in a five-match series.
England had been in a relatively comfortable position at 141-2 before left-arm spinner Jadeja, again preferred to star off-break bowler Ravichandran Ashwin, was eventually rewarded for a probing spell on a wearing pitch.
Haseeb Hameed, 43 not out overnight, had become becalmed at the crease, adding just 20 more runs in 108 balls on Monday.
But his defence was pierced by a Jadeja delivery that pitched just outside his leg stump before turning sharply and clipping the top of the right-handed opener's off stump.
Ollie Pope, who made 81 in the first innings, was bowled for two by Bumrah, gaining reverse swing, giving the fast bowler his 100th Test wicket.
Bumrah then took his second wicket in five deliveries when a brilliant yorker clean bowled Jonny Bairstow for a duck.
Moeen Ali was powerless to prevent further collapse, the all-rounder also falling for nought when he deflected a Jadeja delivery that turned and bounced out of the rough straight to short leg.
England had resumed on 77-0, with Rory Burns 31 not out.
History, however, was against the home side as the most they have made to win in the fourth innings of a Test is 362-9, requiring 359, against Australia at Headingley in 2019.
But Ben Stokes, whose unbeaten century took England to that thrilling one-wicket win two years ago, is not playing in this series while the all-rounder takes a mental health break from all cricket.
And no side have made more to win in the fourth innings of a Test at the Oval than England's 263-9 against Australia way back in 1902.
Burns and Hameed had denied India an early breakthrough on Sunday after the tourists had piled up 466 in their second innings, with Rohit Sharma scoring 127.
Umesh Yadav and fellow paceman Bumrah opened the attack on Monday, with the pair both bowling a significantly fuller length and straighter line than on Sunday.
However, it was all-rounder Thakur — playing in his first Test since suffering a hamstring injury in the drawn series opener in Nottingham —who ended the opening stand.
With just his fourth ball of the innings, and one delivery after Burns had completed a fifty to take England to 100, Thakur's excellent leg-cutter to the left-hander took the outside edge and was caught by wicketkeeper Rishabh Pant.
Hameed completed a 123-ball fifty — his fourth in five Tests — before he mistimed a needless slog-sweep off Jadeja only for Mohammed Siraj to drop a routine catch at mid-on.
But Dawid Malan fell for five when, slow to respond to Hameed's call, he was run out by substitute Mayank Agarwal's throw from cover to Pant.