Malahide - Sri Lanka captain Angelo Mathews said his side will have to be at their best to beat England in the five-match one-day international series which starts on Tuesday.
Mathews was speaking after overseeing a 2-0 ODI series victory over Ireland in Malahide after the second match was won by an emphatic 136-run margin on Saturday.
Opening batsman Kusal Perera, who would have missed the tour had a drugs ban not been rescinded following a faulty doping analysis, made a century to build the platform for his side's huge total of 377 for 8.
"We still can improve a lot in all departments. It was a pretty convincing victory today, but we need to be at our best to beat England," said Mathews.
Eoin Morgan's England have improved dramatically in 50-over cricket since the Sri Lankans thrashed them by nine wickets in Wellington during last year's World Cup.
Saturday's win was set up by dynamic top-order batting, and Mathews said: "Perera and Danuska Gunathilaka had a brilliant opening partnership (147) and after that solid foundation it was a tactical decision to bring in the pinch-hitter and take the game forward."
Seekkugge Prasanna came in a three to pinch-hit in explosive style, bludgeoning nine sixes and five fours to leave his previous best ODI score of 42 far behind with 95 from just 46 balls.
"It was a very good wicket and a tough ask for the bowlers but we stuck to our task," explained Mathews.
"They had to bowl good lines and lengths. Having said that, after scoring 377 it was a tough ask for the Irish because they had to go at it from ball one, so we had to bowl dot balls and create pressure," the all-rounder added.
The fifth and sixth overs of the Ireland reply were maidens and when captain William Porterfield was out to the first ball of the seventh over, Ireland, who have never beaten Sri Lanka in five attempts, could not cope. It needed a last wicket stand of 54 between Andrew McBrine and former England international Boyd Rankin to get the Ireland total over 200.
The man of the series was Sri Lanka's Dasun Shanaka, who scored 42 off 19 balls and took five wickets on his debut in the tourists' 76-run win in the first match on Thursday and Mathews has high hopes for the 24-year-old.
"Shanaka is becoming a very good all-rounder for us and hopefully he will continue in the England ODIs and for the next few years," the captain said.
"We were short of seam-bowling all-rounders, but now with Farveez Maharoof, Shanaka and myself, we have plenty of options."
Perera took advantage of the very good pitch to score 135, his second ODI century, before he was the second of three dismissals in the space of five balls.
He faced 128 balls, with 16 fours and two sixes, and was happy to play second fiddle to Prasanna, who dominated an electrifying second-wicket stand of 161 in 89 balls.
The late flurry of wickets allowed Ireland to restrict Sri Lanka to 67 from the last eight overs, when a total of 400 had looked likely.
Suranga Lakmal was Sri Lanka's most successful bowler. Sharing the new ball with Mathews, he dismissed both Ireland openers in the space of 10 balls, broke the stubborn seventh wicket stand between Stuart Poynter (36) and McBrine (79 off 64 balls) and added a fourth wicket at a personal cost of just 38 runs.
Prasanna completed a fine all-round game with two for 32 from eight overs, and although Shanaka took only one wicket in his second game, it was the big one of the dangerous Kevin O'Brien.