Captain was full of praise for Sangakkara's knock, but was already casting his mind forward to the next do-or-die clash.
Champions Trophy: Cook hails Sangakkara's fine hundred as England get ready for quarter-final
Alastair Cook will quickly refocus his side on Sunday's must-win clash with New Zealand after Kumar Sangakkara's superb century left England's Champions Trophy hopes in the balance.
England looked well on the way to a second second win in their home tournament, and a guaranteed place in the last four, when they posted 293 for seven against Sri Lanka at The Oval.
But the winning target was well within the scope of the imperious Sangakkara, who hit 134 not out in 135 balls to see his side home.
Pinch-hitter Nuwan Kulasekara also played his part as Sri Lanka romped home by seven wickets, smashing five fours and three sixes after being surprisingly bumped up the order to finish the job.
The result leaves England needing a win over the Black Caps in Cardiff to be sure of progressing from Group A.
Cook was full of praise for Sangakkara's knock, but was already casting his mind forward to the next do-or-die clash.
"I think the difference was an outstanding hundred from an outstanding cricketer, that was the difference today," he said.
"Sometimes you come up short against a guy who plays as well as that and you don't feel quite so bad.
"We tried a few different things but in that 130 he didn't give a chance.
"It's not as if we can sit here and say we had our opportunities, that was just a very fine hundred.
"(Almost) 300 wins you a lot of games of cricket. It didn't today because of a very fine innings from Sangakkara.
"Clearly we had an opportunity to get into the semi-final today and didn't take it but we've got another one in our next game.
"This is why the Champions Trophy is such a good tournament, every game means something and you're against quality opposition all the time.
"This opportunity slipped us by and we've got to win on Sunday. It's still in our hands."
Whether or not it is in England's hands could yet depend on the Welsh weather.
Forecasts are not positive at this stage but Cook is not allowing himself to be too down-hearted.
"I've just been told the forecast is not great but I'm not sure I'm too trusting of the British forecasts when it's still three days out," he added.
Sangakkara saw some of the pressure lifted from his shoulders in the closing overs by Kulasekara's swashbuckling and unexpected 58 not out.
Asked if he had expected the tail-ender to come out ahead of skipper Angelo Mathews and Dinesh Chandimal, he said: "It is strange isn't it? If that didn't work, the team would have been torn to shreds.
"Angelo would have taken some criticism saying, 'what was he doing or what were the coaches thinking'.
"Decisions like that can go both ways but I thought it was really strong of Angelo and the coaches to take that decision.
"It was great to see how it worked. Kulasekara batted very sensibly and that's why it worked. It would have been easy for him to come in and try to hit every ball but he batted sensibly through the powerplay and accelerated after."
Sri Lanka face Australia on Monday in their final group clash.