The Spaniard became became the first ATP teenager to reach the quarterfinals at the Internazionali BNL d’Italia since Novak Djokovic in 2007.

"Playing in the U.S. in general is always great," said the 20-year-old, "but staying at a house feels a little bit more like home."

The third seed was a 6-3, 3-6, 6-1 winner against his fellow NextGen American.