Australian Nick Kyrgios, unfazed by stern words from vanquished Rafael Nadal, produced another gritty win over Switzerland's Stan Wawrinka to reach the semi-finals of the Mexico Open.

A day after his dramatic comeback victory over 17-time Grand Slam winner Nadal, Kyrgios out-lasted Wawrinka 7-5, 6-7 (3/7), 6-4 to book a meeting with John Isner for a place in the final. Third-seeded Isner defeated eighth-seeded John Millman 7-6 (7/2), 6-7 (4/7), 7-6 (7/4) in a three hour, five minute marathon on Thursday night.