Sehwag (117) began the four-match series with a memorable statement of intent for India, only for Swann to hit back with four wickets – the second of which took him past the great Jim Laker as England’s most successful off-spinner.
Thanks to Sehwag and Cheteshwar Pujara (98 not out), India nonetheless finished in the ascendancy on 323-4 after a day when England did not always help themselves – putting down two catches and missing two other obvious opportunities to effect dismissals.
Sehwag dominated a century opening stand with Gautam Gambhir, and was then joined by Pujara for another partnership of 90 for the second wicket.
There was little cheer at that point for the tourists, after losing the toss on a pitch likely to increasingly favour spin.
Sehwag wasted no time in grasping an ominous initiative at the very start of the series.
On an especially slow surface, he made a nonsense of his last experience against England – two golden ducks at Edgbaston, in India’s 4-0 defeat last year.
As if to encapsulate the difference 4,000 miles can make, back on home ground he seized mercilessly on any off-side width and angled runs expertly into gaps in a run-a-ball innings.
The first hour gave England precious little encouragement; the second surely a chastening sense already of their undertaking as new captain Alastair Cook tries to lead his country to a first series win in India since the winter he was born.
The Indian openers were quickly in cruise control, before Sehwag upped the ante – and by the first ball of the 20th over, the total was already in three figures.
Sehwag dispatched Yorkshire’s Tim Bresnan, on for James Anderson after eight overs, for four, four and six in successive balls – past cover, wide of mid on and back over his head – forcing Cook into more changes.
Early afternoon brought three let-offs for India, two of them costly.
Matt Prior dropped Sehwag on 80, down the leg side off Anderson, and in the next over missed a stumping chance when Gambhir overbalanced against Swann (4-85).
The left-handed opener did not add to his score before Swann got one to skid on and bowl him on the back foot to end a stand of 134.
But Sehwag soon reached three figures, from 90 balls, with a 15th four lofted over mid on off Swann to go with his six – his first hundred for almost exactly two years, against New Zealand on this same ground.
Pujara was not dropped but nonetheless had fortune, and an England slip, on his side on eight when Anderson overcommitted himself at mid on and could not then reach a leading edge off Bresnan.
The No 3, who had given England a preview of his capabilities with an innings of 87 against them for Mumbai A two weeks ago, is not prone to making a second mistake on the same day.
So it was that he soon had a look of risk-free permanence.
By the time Sehwag missed a sweep and was bowled to take Swann past Laker, England had five men on the boundary to the India opener.
But his departure altered the pace of the game.
First it brought Sachin Tendulkar to the crease, to the obligatory delight of the crowd.
But the veteran master batsman did not last long, holing out in the leg-side deep off Swann – who took two wickets for 11 runs in a four-over spell just before tea.
Afterwards, he continued to make progress slow for the hosts, Virat Kohli needing 30 balls to get off the mark – with a straight-driven four off Stuart Broad – and then dropped at slip on five by Jonathan Trott via a faulty cut at Swann.
After just four runs had come from seven overs immediately after tea, Kohli was undone by Swann anyway – bowled through the gate by a perfectly-pitched off break.
Pujara, meanwhile, was going nowhere fast.
After a 67-ball half-century, he ground to a near halt in the 80s – and the final session brought only 73 runs.
His longevity continued, however, and persuaded England to give Swann a break and their pace attack a second chance with a new ball – to no avail by stumps.
Sehwag’s 23rd Test century was his first for almost two years.
“Every hundred is important,” said the destructive opener.
“This one was due, after two years. So I’m very pleased to have scored one after a long time ... and at the right time, in the first innings of the first Test.”
He has helped to put India in apparent control, but warns 20 England wickets will be hard-earned.
“The first three batsman were trying to hit (big shots) and got out,” he said.
“If you try to block, it’s difficult to get out. The wicket is very slow; it’s turning, but not sharply.”