Flintoff and Pietersen have become indispensable to England

Pietersen scored 142 on Friday in England's first innings total of 295.

"The difference between the teams was KP's knock," Flintoff told BBC Sport. "Whoever saw it witnessed something special - who knows how good he can be?

"It was a comfortable win in the end, but hard-fought as the wicket probably suited them more than us."

Interview: England skipper Andrew Flintoff

Interview: England's Kevin Pietersen

Flintoff added that his decision to bowl far fewer overs than he did at Lord's, where he sent down 51 in Sri Lanka's second innings, was because of the pitch and not to protect himself.

"I bowled more overs than normal in the last Test because I try to bowl to the circumstances," said Flintoff.

Alastair Cook's 34 not out in the second innings was fantastic against Murali England coach Duncan Fletcher

"This pitch wasn't my type of pitch, it suited Matthew Hoggard and Liam Plunkett better, those bowlers who hit the surface and move the ball around."

In addition, Flintoff was delighted to hear that Michael Vaughan is in Yorkshire's squad for the C&G Trophy game against Scotland on Monday and said he is looking forward to him returning to England's line-up.

"It's great news and hopefully he'll be back sooner rather than later," said Flintoff.

"It's been fantastic doing the job as England captain but it's a temporary job - he's the one who's taken the side forward in the past three years.

We didn't do the hard work and let balls go through, we wanted to score runs Mahela Jayawardene Sri Lanka reaction

"Maybe further down the line if the job became available I'd be interested. But with Michael back I can just get back to my day job."

Meanwhile, England coach Duncan Fletcher praised the newer players in the side, especially Plunkett, who took six wickets in the match, and batsman Alastair Cook.

"The youngsters played well and they're improving with every match," said Fletcher.

"Alastair Cook's 34 not out in the second innings was fantastic against (Muttiah) Muralitharan and Plunkett came on and suddenly changed the game this morning."