With the Sri Lankan spinners having shown the way earlier in the evening, the choice in England's huddle was fairly straightforward. Harry Brook had to decide which finger spinner would bowl the second over. It was either going to be Will Jacks or Liam Dawson. He backed Jacks. And it didn't take long for that call to pay off.

Jacks began quietly enough, conceding only four runs in his opening over as England searched for early control after finishing with only 146 for 9 on a slow surface - a total the England captain felt was 15-20 runs short. At the other end, Jofra Archer struck the important blow by removing the in-form Pathum Nissanka, giving England the opening they badly needed. Then Jacks took over, and with it the game tilted.

There was little mystery to how Jacks went about it. He stayed stump-to-stump, varied his pace and trusted the surface to do the rest. England had done their homework too. Pavan Rathnayake, who England identified as Sri Lanka's strongest player of spin, lasted just one ball, and the reaction from Jacks and his teammates showed exactly what that moment meant to England. "We knew that he was probably their best player of spin, the way that he runs down the pitch as well. So to get him out first ball was a very crucial part in the game for us," said Brook, pointing to that dismissal as a key moment.

By then, the squeeze had properly begun. Kusal Mendis had already chipped one back, Rathnayake followed immediately, and when Dunith Wellalage miscued later in the Powerplay, Sri Lanka were in deep trouble. Three wickets for Jacks inside the phase were not just timely, they were defining blows, and Sri Lanka's chase never recovered from the early damage. With Archer also striking twice from the other end, including the scalp of Kamil Mishara, England had effectively wrapped up the game inside the Powerplay when Sri Lanka slipped to 34 for 5.

With their batting not quite taking off again, England's bowling plans needed to be clear. The discussion at the halfway mark centred on the spinners doing the heavy lifting, with variation, accuracy and changes of pace being the key themes on a pitch that wasn't all that bad, according to the England skipper.

"Yes, it probably wasn't as bad as the scores say, but it was very slow and both sides with the spinners bowled exceptionally well. You could obviously tell the modes of dismissal were caught and bowled, and lack of pace and we had a chat before going out there with Rash and Dawson, Jacksie, it was like we didn't really need to change our lines, it was more changing our paces and trying to make them make a mistake."

Jacks fitted that brief perfectly, as he would admit himself later. "I love getting that responsibility with the ball. I think it encourages me to get into the game and perform better. I think I like that responsibility and bowling in the powerplay is something I've done a lot. So it's not foreign to me. And when we get on the surface like that, I come into the game knowing what I need to do," he told the broadcaster after winning the Player of the Match award.

Jacks had finished his spell at the end of the eighth over. But he wasn't done having an impact on the game yet. When Sri Lanka's captain Dasun Shanaka hit a couple of big blows and threatened to bring the chase back on track, it was Jacks again - sprinting across to his left at deep midwicket to take the catch on the move, aware of the rope behind him and sharp enough to flick the ball to Tom Banton before the momentum carried him over.

That catch, as much as anything he has done with bat or ball, spoke to how often Jacks has arrived at exactly the right moment in this campaign.

Against Nepal, he walked in with England wobbling at 137 for 5 in the 16th over and struck an unbeaten 39 off 18 to push the total to 184, alongside a wicket with the ball. Against Italy, he entered at 105 for 5 and hammered a 21-ball fifty - England's quickest in men's T20 World Cups - before again contributing with the ball. Even in the tight finish against Scotland, his unbeaten 16 helped close out the chase.

Pallekele added another layer: a brisk 21 off 14 earlier in the evening to push England towards the 140 mark after Phil Salt's dismissal, followed by a powerplay spell that broke Sri Lanka's back. It also offered a glimpse of the competitive intensity Jacks brings to this England side, especially when he is slightly fired up.

"He's just that perfect player really and he's the jack of all trades, he can do everything and he's awesome in the field, with the bat and then like we've seen tonight he was very good with the ball," said Brook, who also explained why Jacks was rather angry heading into the second innings. "He's a very competitive lad. He was annoyed when he got out tonight and I think after his first over he was like, 'I always bowl better when I'm annoyed'. So that was one of the reasons why I kept him on and bowled him four overs."

Jacks now has three Player of the Match awards in this tournament, just one short of Shane Watson's record of four in the 2012 edition. Brook believes there is more to come. "He's had three Man of the Match awards so far in this World Cup and I still don't even think he's played his best cricket yet. So that's another exciting thing that we can hopefully witness when he gets going with the bat as well at the back end."

For England, Jacks' consistent contributions are an encouraging sign in a campaign where they have not always looked fluent, particularly against spin with the bat. What they have done, however, is keep finding ways to win.

Jacks too acknowledged they have not been at their best but stressed that the important thing was the results. "We haven't quite been at our best, but importantly, we've been winning those close games...We know we're good enough and we know if we play with that freedom and that unity that more often than not we'll be in the right position." For now, England will gladly ride on Jacks' growing influence.