Just one more victory separates Lexington native Jasper Johnson from receiving a gold medal. On Saturday in Buenos Aires, Argentina, Johnson and Team USA dominated from the jump, cruising past Canada in the semifinals of the FIBA U18 AmeriCup by a final score of 107-69. The Americans will now await to take on the winner of the Dominican Republic vs. Argentina. The gold medal game is scheduled for Sunday at 5:10 p.m. EST. Team USA has won gold in this event 10 out of a possible 12 times, dating back to 1990. After coming off the bench in Friday’s quarterfinal win over Puerto Rico, Johnson did t…