ATLANTA — For the first time, Brian Gregory saw signs of the team he wants Georgia Tech to become. The winning style of play came through when Gregory, the second-year coach, needed it most. Georgia Tech rallied from a halftime deficit of nine points, finally taking the lead on Mfon Udofia’s jumper with 1:19 remaining, and beat Virginia 66-60 on Sunday to end the Cavaliers’ four-game winning streak.