At stumps, England were closing in on a first innings lead at 138 for three after paceman Liam Plunkett had taken three for 43, including a double-wicket maiden in his first over.
That was after Mahela Jayawardene had won his first toss in six Tests as Sri Lanka skipper and elected to bat on a good pitch here on Thursday.
"The wicket had just a bit in it for the first hour-and-a-half but it turned out to be a great wicket to bat on," Sangakkara said.
"When you win the toss and elect to bat, 300 plus is a good first innings total. It was disappointing," he also told reporters after Thursday's close.
The wicket-keeper was only one of four Sri Lankan batsmen who made it into double figures and but for a ninth-wicket stand of 50 between Chamina Vaas (30 not out) and Lasith Malinga, the tourists - who batted gamely to draw the first of a three-match series at Lord's, would have struggled to get past 100.
"We really don't need the ninth-wicket pair to show the batsmen how to bat. It's up to us from the top order to the middle to set a total and look to the tailenders to put the icing on the cake.
"Today, the tailenders buckled down to the job in the way the top-order should have."
It was the second time in as many Tests that Sri Lanka's batsmen had struggled in the first innings after being dismissed for 192 at Lord's, although they did then rally superbly to save the game.
Plunkett, 21 and playing in only his fourth Test was well-supported by fellow quick Sajid Mahmood (two for 25), who made his debut at Lord's.
However, Sangakkara said: "We made the England attack look a bit better by the way we batted. To have the same thing happened here (as at Lord's) is not the ideal situation for us."
But he did praise England's young quicks, saying: "The key is to build up pressure by bowling dot balls and putting the ball in the right areas. That's the impressive thing about England's attack, they just keep working away."
Sri Lanka chose to omit veteran opener Sanath Jayasuriya after the former captain recently ended his Test retirement and arrived in England during the Lord's match.
But Sangakkara insisted the team was good enough to prosper in the 36-year-old left-hander's absence.
"The key is we have the quality, we have the talent to do much better than that (score 141). Everyone in the management, plus the team and everyone back home had enormous faith in what our players can do."
Meanwhile, a proud Plunkett said: "It was nice to pick up two wickets in my first over. I felt really good this morning, straight from the word go. I just ran up and hit my areas."
He added: "We've got enough batting in the dressing-room to go out now and get a big lead and hopefully knock them over cheaply in the second innings."