Roberto Castro has maintained his lead at the AT&T National at Congressional, but he has been joined at the top of the leaderboard by youngster Jordan Spieth.
Castro consolidated his opening-round 66 with a solid second attempt of 69, but he was joined by 19-year-old Spieth.
Spieth is competing in just his 22nd PGA Tour event, but he remained composed to record a 66.
Almost half of the field have yet to complete their second round due to a three-hour delay for a thunderstorm, with Andres Romero still having five holes to play after moving into a share of third place.
Cameron Tringale and James Driscoll are on four-under-par, while Bill Haas and Nick Watney look threatening on three-under, with over half of their second round still to play.
