A fuming Thanasi Kokkinakis took a swipe at Fernando Verdasco in a heated mid-match argument after the Spaniard complained about the Aussie's dad.
Spanish veteran Verdasco battled to a 3-6 6-4 7-6 (7-4) win over Kokkinakis, who knocked Swiss world No.1 and defending champion Roger Federer out of the Masters 1000 event.
The match included a heated exchange between the pair about the Australian qualifier's father at a change of ends in the third set.
Verdasco seemed to be complaining about the Aussie's dad talking between his serves but when confronted over it, assured Kokkinakis that it wasn't his father he was angry at.
"No it's not your dad it's the guy on the left with the hat," Verdasco explained.
"Which hat, which hat?" Kokkinakis fired back as he turned to where his father was sitting in the stands.
When Verdasco revealed that it was the man wearing glasses that he was annoyed with, Kokkinakis was clearly infuriated.
"That's my f***ing dad!" the Aussie yelled back.
The Spaniard apologised for offending Kokkinakis before explaining that he thought it was the Aussie's coach who was talking between serves.
The fiery exchange cast an ugly shadow over a gripping contest, where unfortunately for Kokkinakis, his giant-killing run came to an end.
Things went better for the Aussie's compatriot Nick Kyrgios, who breezed into the round of 16 in Miami.
The 17th seed took a tick over an hour to seal a routine 6-3 6-3 over 15th-seeded Italian Fabio Fognini.