In a largely young 3M Open field, the tournament's oldest competitor made a push toward the top of the leaderboard in the second round. Stewart Cink, 51, started off Friday with back-to-back bogeys at TPC Twin Cities in Blaine. But the 2009 British Open champion didn't panic. An eagle on the next hole set him back on the right track, and he finished the day 7 under par after shooting 69, tied …