Jennings (112) made the most of some early fortune on day one of the fourth Test – dropped on nought by Karun Nair at gully off Umesh Yadav, and also surviving a close umpire’s call for lbw against Bhuvneshwar Kumar – on his way to a 186-ball hundred at his first attempt.
He is the 19th England batsman to mark his debut with a century and it was a contribution which may well have put England ahead of the game with a stumps total of 288 for five after Alastair Cook won a crucial toss.
The 24-year-old South Africa-born opener was assured after his early scrapes and there were several convincing cover-drives and pulls among his 13 boundaries – in stands of 99 with Cook and 94 with Moeen Ali (50) as England negotiated the wiles of Ashwin (four for 75).
Jennings, Cook’s 11th opening partner since Andrew Strauss’ retirement four years ago, was dropped just before he got off the mark with a cut for four off Umesh – from the 12th ball he faced. He went on to complete his hundred with a reverse-swept four off Jayant Yadav as he put England in position of promise, seeking to battle back in the series from 2-0 down with two to play.
England were putting into action coach Trevor Bayliss’ instruction to return to batting with ‘intent’, as in last month’s drawn opener in Rajkot.
But it was an approach which would cost Cook his wicket four short of his 50, in atypical fashion for England’s greatest accumulator of runs, when he went up the pitch in Ravindra Jadeja’s first over and fell to a juggled stumping by Parthiv Patel as the ball turned and bounced between bat and body.
England then also lost Joe Root soon after lunch, edging an attempted push-drive at Ashwin to slip. But Moeen, scratchy at first and after several flirtations with the slips off both pace and spin, played with increasing conviction until – straight after reaching his half-century – he miscued an attempted slog-sweep to short midwicket from the first delivery of a new Ashwin spell.
When Jennings went as well, edging some extra bounce to gully two balls later, England suddenly had work to do again – with Jonny Bairstow and Ben Stokes thrown together on nought.
The former, so prolific with the bat this year, fell cheaply for once - to a sweep at Ashwin straight to deep backward-square. But on a pitch already providing significant assistance for the spinners, Jennings had arguably done plenty already to give England the opportunity at least to cement a telling advantage.
Meanwhile, umpire Paul Reiffel had to leave the field after being felled by a blow to the back of the head at square-leg from Cheteshwar Pujara’s lobbed outfield throw.
Reiffel went to hospital for CT scans, which came back clear. He returned to the ground but was advised to rest for the remainder of the day.