With his wrist aching and temper fraying, Juan Martin del Potro turned to his strength. The U.S. Open champion fired 21 aces -- one at 135 mph -- to overpower American Michael Russell 6-4, 6-4, 3-6, 6-2 in the first round of the Australian Open on Monday. Del Potro, a 6-foot-6 Argentine seeded No. 4, played with his right wrist and forearm taped to stave off a recurrence of tendinitis. More...