Pietersen arrived at the crease under mounting pressure, having not scored more than 32 in eight innings this winter.
But the 31-year-old insisted he felt in good form coming into the match and this appeared to be the case as he brutally took on Sri Lanka’s bowling attack.
“In the last one-day series in Dubai and Abu Dhabi, and into the T20s, and into the Test series here I have felt in fantastic form so it was just a case of cashing in when you’re in good nick,” he said.
The Sri Lankan bowlers suffered, in particular Suraj Randiv, who conceded 15 off one over as Pietersen brought up his 20th Test century off just 109 balls, including 11 fours and four sixes.
“The amount of cricket we play now, it doesn’t matter if you are playing one-day or Tests, it all rolls into one. It’s just a different approach. I played in one-day mode today,” he said.
However, Pietersen’s innings was not without controversy as his repeated use of his signature switch-hit, legitimised by the MCC in 2008, saw him receive a warning for time-wasting from umpire Asad Rauf.
He was cautioned for altering his stance before the bowler’s delivery stride as Tillakaratne Dilshan twice refused to bowl when Pietersen reset his position at the crease.
Alastair Cook and Jonathan Trott had begun the day well, taking England’s overnight score of 154-1 to 213, before Cook was caught at slip for 94 – the second time this winter he has fallen six runs short of a century.
Trott fell for 64 with the score at 253, but a good partnership between Ian Bell and Pietersen gave England the lead.
England will perhaps be a little disappointed that both Bell and Matt Prior were guilty of giving their wickets away, an all too familiar sin for their batsmen this winter, but 29 from Samit Patel and 17 from Graeme Swann ensured that they ended their innings with a lead of 185.
Sri Lanka had the unwelcome task of seeing out an over from James Anderson before the close of play and sent in Dhammika Prasad as a night-watchman along with Lahiru Thirimanne. Anderson conceded four leg byes and had a strong LBW appeal rightly turned down due to an inside edge, as Sri Lanka ended on 4-0.
Pietersen himself hinted at some dressing room frustration at yet another batting collapse.
“We have got ourselves in a good position in the Test match but in the last session we may have let ourselves down,” he said.
“Tomorrow will be an interesting day’s cricket.”
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