Spinner Graeme Swann became only the second bowler in Test history to claim two wickets in his first over on debut as England ripped through India's famed top-order batsmen to put themselves in the driver's seat in the first Test in Chennai on Friday.
After restricting England to 316 in the first innings, the Indians lost the plot completely, as a shocking batting collapse left them tottering at 155 for 6 at close on an eventful second day.
It was off-spinner Swann who started India's slide with sensational twin blows that accounted for the prized scalps of Gautam Gambhir and Rahul Dravid and the Indians never really recover from those early jolts.
Captain Mahendra Singh Dhoni (24) and Harbhajan Singh (13) were unbeaten at stumps, with India still trailing by 161 runs.
Debutant Swann is only the second bowler to take two wickets in his first over in Test cricket. Richard Johnson of England was the first to achieve the feat, against Zimbabwe in 2003.
None of the Indian batsmen could hang around for long on the M A Chidambaram track which has started providing some assistance to the bowlers.
With the pitch expected to deteriorate further, the Indians will have to ensure that they don't concede a big first innings lead since they have to bat last.
Earlier, Indian spinners Harbhajan Singh and Amit Mishra shared six wickets to bring down the curtain on England's first innings around 37 minutes after lunch.
Yuvraj Singh and Ishant Sharma claimed a wicket each as the visitors added only 87 runs to their overnight score of 229 for 5 before being dismissed.
Matt Prior (53 not out) waged a lone battle against some top quality bowling by the Indians.
The Indian innings began on a disastrous note as the in-form Virender Sehwag was dismissed cheaply and then Swann's two-wicket burst left India tottering on 37 for 3.
Perhaps taking the cue from rival captain M S Dhoni, whose ploy to persist with spinners in the first hour proved successful, England skipper Kevin Pieterson brought on Swann from the pavilion end in the 14th over with a few minutes remaining for the tea break.
Swann's first ball was dispatched to the cover fence by Gambhir, who then survived a confident appeal for a bat-pad off the very next ball, umpire Daryl Harper remaining unmoved. But then he had to walk back after being rapped on the pads by Swann.
Sachin Tendulkar then walked out to bat to a thunderous welcome on one of his favourite grounds. He took a single and gave strike to Dravid. The former India captain became Swann's second victim when he played forward to a turning ball from outside the off stump and was rapped on the pads in front of the wicket.
Tendulkar and the stylish VVS Laxman tried to retrieve the situation for the home team and looked quite comfortable in the middle. The experienced duo stitched 61 runs for the fourth wicket before left arm spinner Monty Panesar provided the vital breakthrough by getting rid of Laxman (24) with a brilliant return catch.
Tendulkar (37), who seemed in fine nick, joined Laxman in the pavilion soon after with Andrew Flintoff plotting his dismissal. He offered a simple return catch to Flintoff, who made no mistake.
Earlier, England new ball bowlers blasted their way for dot balls, using their shoulder power to lift the ball high to Indian batsmen, who were content to leave the deliveries without offering any stroke on many occasions.
Both Harmison and Anderson bowled with venom and bounced the ball shoulder high. Fishing outside the off-stump, Sehwag, who hit a triple ton in his last match against South Africa at the venue earlier this year, scored his first boundary, nudging Harmison's ball through the slips.
He showed his class while pushing one from Anderson in the sixth over to the long-off fence, but perished to the very next ball. Trying to guide a delivery that came in, he dragged it on his stumps with the team score on 16.
With Andrew Flintoff, who replaced Harmison in the ninth over, also extracting good bounce, Gambhir and Rahul Dravid played cautiously.
In the morning, England could muster just 65 runs from the 29 overs they faced in the first session, losing Andrew Flintoff (18), James Anderson (19) and debutant Graeme Swann (1) in the process.
When England resumed at the overnight scored of 229 for 5, Dhoni, who chose not to opt for the new ball, opened the second day attack with Ishant Sharma. But after the wicket started to offer bounce and movement, he swapped Amit Mishra for the pacer.
Mishra responded magnificently as he came up with a slower one to Flintoff, who played forward, but only to offer an inside edge. Gautam Gambhir, at forward short leg, did a neat job, diving to his right to collect the catch.
Both James Anderson and comeback batsman Matt Prior were looking to settle down but yet again were uncomfortable against Mishra.
England wilted under pressure and lost the wicket of Anderson, who was caught by Yuvraj Singh at midwicket off Mishra.
In fact, Anderson was lucky to have survived early in he day when Rahul Dravid dropped a sitter at slip. Anderson, who slashed Mishra, was on six, and his departure left England on 243 for six.
Harbhajan kept up the good work and scalped debutant Graeme Swann. The Indian off-spinner bowled a quicker one and Swann, in an evasive action, offered his gloves to it and this time Dravid made no mistake, taking a low catch.
