Ashes: 1st Test, Day 2
Match report | Scorecard
Michael Clarke survived a chance on 21 when Pietersen dropped a simple catch at covers off Simon Jones.
It was his third drop of the match but by far his loudest clanger as Clarke hammered the English bowlers to score 91.
The 24-year-old, who has scored centuries on his home and away Test debuts, missed the chance of a century on his first appearance at Lord's as he slashed an inside edge into his stumps off Matthew Hoggard.
