American Steve Johnson advanced to the second round of the Mexican Open with a surprisingly easy 6-4, 6-4 win over countryman John Isner on Monday night. The 27 year-old Johnson, who is ranked 24th in the world, needed only 65 minutes to take care of Isner, who was seeded eighth in Acapulco and No. 22 in the ATP rankings. It was Johnson*s third straight win over Isner.