Caroline Wozniacki made light work of Christina McHale as she progressed into the quarter-finals of the Auckland showpiece event.
Wozniacki had a fast start as she took the first set 6-0 against the shell-shocked American.
The former world number one almost secured the 'double bagel' as she had a match point at 6-0, 5-0. However, McHale refused to give up easily and won two games on the bounce before Wozniacki finally ended the match.
"I felt like I played really well today. I’m really pleased," said the Dane as she reflected on the match.
Naomi Broady let her racquet do the talking against Jelena Ostapenko in a fiery match that was marred by an on-court row after the Briton called for the Latvian to be disqualified when the latter threw her racquet and it hit a ball boy.
The umpire opted for a code violation rather than a disqualification after Ostapenko claimed her racquet slipped from her hand.
At one set apiece, Broady looked finished as she trailed 1-5 in the third. However, the British number three saved two match points as she clawed her way back to prevail 4-6, 7-6, 7-5.
“Jelena commented that my behavior was terrible. Which I thought was a bit out of order, considering the events that had gone on in the match," Broady said of her confrontation with her opponent that took place during the match.
In the day's other match Julia Goerges beat Barbora Zahlavova Strycova 6-4, 7-6 to book her place in the last eight.