Singh bounced back from two early bogeys, went on a stretch of eight birdies in 13 holes, then saved for bogey on the 18th with a memorable shot from the edge of the water. He went into the clubhouse at Congressional with a one-stroke lead over Jon Rahm, who had an afternoon tee time.
The 53-year-old Singh hasn't won on the PGA Tour since 2008. He's halfway to becoming the oldest PGA Tour winner in history but said he wasn't thinking about making that kind of history.
Sixth-ranked Rickie Fowler is in the clubhouse two strokes back of Singh after shooting a second-round 68.
