British number two Cameron Norrie reached the ASB Classic quarter-finals with a straight-set victory over Joao Sousa in Auckland.
World number 93 Norrie beat the Portuguese, who is ranked 49 places above him, 7-6 (7-4) 6-4.
The 23-year-old saved all six break points he faced as he closed out the match in 95 minutes.
He will face 50th-ranked Taylor Fritz in the last eight after the American stunned top seed John Isner.
Fritz beat big-serving Isner, ranked 10th in the world, 7-6 (7-3) 7-6 (7-5).
The event is one of the last before the Australian Open starts on 14 January.