Juan Martin Del Potro runs his 2011 record to 20-5 after upending No. 4 Robin Soderling 6-3, 6-2 in Miami. The 2009 U.S. Open champion scored his first win over a Top 10 player in 16 months and will next face American Mardy Fish, whom he beat last month in the semifinals of Delray Beach.

"It’s a long road to come back and being in the top again, but I am trying to be calm," said No. 51 Del Potro. "The people say, 'You should be in the top very soon' or something like this, but it’s a long road. I’m working every day, improving very, very slowly. Maybe for the second part of the year, I will be ready for fight against the Top 10 players."—Matthew Cronin