England captain Alastair Cook said Thursday's victory over Sri Lanka was "a really important win" as their World Cup preparations continue.
Joe Root made an unbeaten 104 and James Taylor added 68 as the tourists reached their 240 target with five balls left.
"There's a real excitement among the group about what's going to happen over the next three months," said Cook.
"I know we've lost three games, and are still down in the series, but I think we've made some really good strides."
|England one-day internationals in 2014|
England's win reduced Sri Lanka's lead in the one-day international series to 3-2 with two matches remaining.
Early in the new year the team travel to Australia for a triangular ODI series with the hosts and India before the first of their World Cup fixtures takes place against co-hosts Australia on 14 February.
"We've worked incredibly and over a couple of years now on being able to manipulate at the right time and being able to bang and hit sixes," said Cook.
"The way the guys have taken to it in training, and been prepared to take a few risks in the game at the right time, and more importantly execute the shots in the right way, has been fantastic."
Rain in Pallekele on Wednesday took the match to a reserve day after Sri Lanka had been dismissed for 239, Kumar Sangakkara top-scoring for the hosts with 91 from 123 balls.
"I thought the way Sanga played yesterday was a masterclass in batting, and I thought Rooty hit the same level as that," enthused Cook.
"Sanga was brilliant, and when Rooty went on and was there at the end, that was in the same league."
Taylor struck his second successive ODI half-century and his captain said: "He's got a really good head on him. He's gone away and obviously worked incredibly hard on his game."
Sri Lanka captain Angelo Mathews added: "At first, I thought we were about 20 or 30 runs short, but 239 was still challenging on that wicket, because it only got worse.
"It's just that the spinners - apart from Sachithra [Senanayake], 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."