Alastair Cook put Joe Root's "phenomenal" batting in an esteemed bracket after the Yorkshireman's third one-day international hundred of the year helped England to a five-wicket win over Sri Lanka.

Root - who scored an unbeaten 104 - and James Taylor (68), made a mockery of the consensus that England would struggle to chase 240 on an awkward, spinning surface at the Pallekele International Stadium.

Instead, after the loss of both openers, the third-wicket pair put on 104 together and then Root stayed till the end, first in another important stand with Ravi Bopara and then to ensure a minor late wobble did not cost the tourists.

The win helped England reduce the series deficit to 3-2 with two more matches to play, and captain Cook compared Root's batsmanship to the "masterclass" he had witnessed from Sri Lanka great Kumar Sangakkara 24 hours earlier.

Sangakkara made 91 out of 239 all out, eventually falling as one of Chris Woakes' six victims, before rain intervened between innings and left England with what seemed likely to be a tough task on the reserve day.

Thanks principally to Root and Taylor, adding another half-century to his 90 in Colombo four days ago, Cook had plenty to smile about.

"The way we bowled, first of all, was fantastic," he said.

"It's great credit to Chris Woakes that he's got two of the best three sets of figures (for England in ODIs).

"Then the way James Taylor, and particularly Rooty, played was just phenomenal batting today.

"I thought the way Sanga played yesterday was a masterclass in batting, and I thought Rooty hit the same level as that.

"Sanga was brilliant, and when Rooty went on and was there at the end that was in the same league."

The upshot is that England still have a chance of starting their World Cup winter with a much-needed series victory - in difficult climes.

"This is a really important win today," said Cook.

"Obviously, Colombo hasn't been that kind to us, but we've won away from there.

"It would be great to get to Colombo 3-3 (for next week's final match) and have a series final."

To do that, England will have to prevail again here on Saturday.

Cook added: "If we play anything like that, we can put pressure on Sri Lanka. But as we know, the challenge of it is 'Can we back it up?'

"We had a blip in that second game, but the way we've played spin has been good.

"Today was a prime example. To chase 240 fairly comfortably on a spinning wicket ... is a credit to the way we've pushed ourselves, for our skills to go through the roof. I think they have done."

Taylor has been a revelation, in only his third and fourth ODIs - after an absence of 15 months.

"He's got a really good head on him," said his captain.

"He's gone away and obviously worked incredibly hard on his game. He and Rooty, when they needed to take the pressure off themselves, found the boundary but (also) hit the ball to mid-on and going straight away. That's a hallmark of good one-day batting."

Taylor's intent at the crease, calmness and power are all major assets.

Cook is not surprised by his success.

"From the reports we've had from Lions cricket, he's been the stand-out in terms of his mental approach to the game and strength," he added.

"He obviously knows his game, and he knows himself - which, I think, is why he is doing so well."

He is one of a clutch of players - including Woakes and Chris Jordan - to begin making their mark at an especially opportune time, with a World Cup squad to be picked later this month.

"I thought, the way we played over two days, we deserved to win," added Cook.

"There's a real excitement among the group about what's going to happen over the next three months.

"I know we've lost three games, and can't hide from the fact we're still down in the series, but I think we've made some really good strides.

"I'm really happy with the way it's going."

Sri Lanka captain Angelo Mathews was naturally less enthused by his team's performance - excluding, of course, Sangakkara and off-spinner Sachithra Senanayake who took the early wickets of Cook and Moeen Ali in his first match since being cleared of a suspect action.

"At first, I thought we were about 20 or 30 runs short," said Mathews.

"But 239 was still challenging on that wicket, because it only got worse.

"It's just that the spinners - apart from Sachith, who was brilliant in his first match back - didn't bowl well. I was disappointed with them.

"We started bowling well after the 40th over. That was too late for us. All in all, it was a bad performance."