Juan Martin del Potro is playing the best Masters tennis of his career and believes the best is yet to come.

The Indian Wells champion extended his winning streak to 13 matches dismantling Kei Nishikori, 6-2, 6-2, to charge into the Miami Open round of 16 against Filip Krajinovic.

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Del Potro did not drop serve in a 72-minute thrashing reaching the round of 16 for the fifth time in 10 Crandon Park appearances.

While conceding he's tired playing his third straight tournament, del Potro believes he can elevate his game to an even higher level.

"I think I'm playing good. I can play even better, but I need to get confidence playing in this court, trying to keep winning matches," del Potro told the media in Miami. "But is not easy. My body start to feel tight because all my success.

"But I'm enjoying a lot playing this tournament. I would like to stay longer because it's a special tournament for me. Is the last time playing in Key Biscayne, so I would love to stay here few more days."

Del Potro can look forward to an extended break after Miami. The 2016 Olympic silver medalist said he plans to play an abbreviated clay-court scheduled as he did last season.

Last year, del Potro played Estoril, Rome and Lyon as tune-up tournaments to Roland Garros where he reached the third round bowing to Andy Murray.

A year ago, del Potro exited in the second round of Acapulco, Indian Wells and Miami in the lead-up to clay season.

In contrast, this month he's swept successive titles in Acapulco and Indian Wells and has a shot to make a deep run in Miami. The fifth-seeded Argentine is the second-highest seed still standing in the bottom half of the draw next to second-seeded Marin Cilic.

Del Potro's successful spring on North American hard-courts could reduce his spring clay-court schedule. 

"It could be the same (schedule as 2017)," del Potro said. "I've been doing well this beginning of the year. I don't like too much the tournaments on clay, so maybe I quit few tournaments from the start of the season, of the clay season. I will try to be 100 percent for French Open. Maybe some tournaments before the French."

Photo credit: Guillermo Sanchez