Golf-Watson in three-way tie for US Senior Open lead

June 26 (Reuters) - Tom Watson retained his place atop the U.S. Senior Open leaderboard on Friday after shooting a one-under 69 in the second round, but was joined at the top by American Jeff Maggert and Australian Peter Fowler at Del Paso Country Club in California. Playing in the stifling Sacramento heat, the 65-year-old drained four birdies but also had three bogies to drop into a share of the lead with Maggert and Fowler at a five-under 135. Maggert shot a 65 and Fowler 66. Watson, who has won six senior majors as well as eight on the regular tour, is aiming to become the oldest winner of the event and the oldest winner of a Champions Tour major. The leaders have little room to breathe with Bart Bryant, Jim Carter and pre-tournament favourite Colin Montgomerie sitting just one shot back on 136. German Bernhard Langer is part of a group of six sitting another shot away. (Reporting by Cameron French; Editing by Peter Rutherford)