Kyrgios was raging after losing a challenge on his first serve and then smashed down an unstoppable, untouchable second.
Only Ivo Karlovic’s 144mph effort at the 2007 Legg Mason Classic has topped it, according to ATP statistics.
Kyrgios went to the opposite extreme moments later with a gentle under-arm ace.
Nadal won the first set 6-3 but Kyrgios took the second 6-3.
(Reporting by Mitch Phillips; Editing by Alison Williams)