Jessica Pegula reaches Adelaide quarters, Elise Mertens progresses in Hobart

World number five Jessica Pegula battled back from a set down to overcome lucky loser Bernarda Pera 4-6 6-2 6-3 and reach the quarter-finals of the Adelaide International.

The second seed needed two hours and 12 minutes to prevail in the all-American clash ahead of her campaign at the Australian Open, which begins on Sunday.

Pegula looked ill at ease against Pera's powerful left-handed game in the opening set and converted only one of her 10 break point chances.

But she found her feet in the second set to draw level and after nosing ahead by a break at 4-3 in the third she then saved five break points for a crucial hold.

Her sixth break in the next game vanquished Pera, setting up a quarter-final against either Anastasia Pavlyuchenkova or Katerina Siniakova on Thursday.

"(Pera) was hitting unbelievable shots in the first set, I didn't really think there was much more I could do," Pegula said.

"I just tried to change a couple of things, and stay relaxed, not get frustrated that she was playing some great tennis. She's always very tough."

At the Hobart International, another tune-up event for the Melbourne Park Grand Slam, top seed Elise Mertens defeated Anna Karolina Schmiedlova 6-2 6-3 to make the quarter-finals.

At the Auckland Classic, top seed Ben Shelton defeated Fabian Marozsan 6-3 6-4, while third seed Francisco Cerundolo was hammered 6-1 6-1 by Alexandre Muller.

Cameron Norrie continued his Australian Open preparations with victory over Frenchman Luca Van Assche in the second round in Auckland.

The British number one saw off his 19-year-old opponent 6-3 6-7 (6) 6-1 in just under two and a half hours to set up a quarter-final against Chile's Alejandro Tabilo.

Having claimed the opening set, Norrie had match point in the