Ferrer saved 10-of-11 break points in the match -- and needed 70 minutes just to complete the first set -- before advancing to the finals where he will face Polish qualifier Jerzy Janowicz.
Janowicz upended Gilles Simon of France 6-4, 7-5 in a match in which he served up a dozen aces to Simon's three.
Janowicz kept up his strong late-season surge to reach an ATP finals for the first time. He beat Andy Murray in the third round and Janko Tipsarevic in the quarterfinals at Paris, and was a quarterfinalist at the Kremlin Cup in Moscow two weeks ago.
Swim Week Miami Beach 2014 [PHOTOS]