Sam Curran admitted England were surprised by the amount of help the Ageas Bowl conditions gave the India bowlers.
The hosts, who won the toss and elected to bat, were bowled out for 246 on the opening day of the fourth Test at the Hampshire venue.
Curran struck a brilliant 78 to rescue England after they had slumped to 86 for six in the face of a superb new-ball assault from the tourists.
Keaton Jennings (nought), skipper Joe Root (four) and Jonny Bairstow (six) were all dismissed cheaply as Jasprit Bumrah and Ishant Sharma delivered a masterclass in swing and seam bowling.
Curran began the fightback alongside Moeen Ali (40) – the pair marking their return to the side with a stand of 81 for the seventh wicket.
The 20-year-old Surrey all-rounder then found support in the form of Stuart Broad (17) as he hauled England up to 246 before being bowled aiming Ravichandran Ashwin over midwicket.
Curran’s knock spanned 136 deliveries and included eight fours and one six.
And while India eased to 19 without loss before the close, he reckons their total is a competitive one given the assistance on offer.
Curran said: ‘It was tough because it swung massively throughout the day.
‘Even when I was in and the ball was 65 overs old it was still moving consistently.
‘That surprised us a little bit. Just how much it swung and how much it did off the wicket.
‘There were some very good balls in there, too, so it is a massive positive we ended up getting around 250.
‘It looks a good score now considering how much the wicket has done and how much the ball has swung.
‘Our batters got some very good balls. A lot of the top order got very good deliveries and sometimes it just works like that.
‘That is just the way it swings. But it is a team game. We managed to get 246 and after we were 86 for six it looks a decent score.
‘So that is a massive positive for us and we go into day two with a bit of momentum. ‘Hopefully we can get a few early ones in the first session.’
Curran was left out of the third Test – at Trent Bridge – which England lost by 203 runs.
But he insisted he wasn’t out to prove a point following his recall in place of the injured Chris Woakes.
He added: ‘I just tried to play my natural game. I love being in this side and I just try to play with no fear, nice and positive.
‘I was just playing the way I do, just playing naturally and freely. I am not going to change the way I play because it is just who I am.
‘It’s the way I play for Surrey – with no fear. You try to do the best you can for your side. I don’t try to overthink it and luckily it came off.
‘I wasn’t trying to prove a point at all. I was unlucky last week to miss out but I love being around this squad and I am learning so much.’