MELBOURNE, Jan. 23 (Xinhua) -- World number three Alexander Zverev finished strongly on Friday to down 26th seed Cameron Norrie in four sets and power into the Australian Open's last 16.

In the night session on John Cain Arena, the German was engaged in a gripping battle with the third round match locked at a set apiece before Zverev motored to a 7-5, 4-6, 6-3, 6-1 victory in two hours and 46 minutes.

"I'm happy with the win and moving forward," Zverev said.

Zverev, last year's beaten finalist, was keen to lift his level after an unconvincing start to the tournament where he was pushed to four sets in each of his first two matches.

The 28-year-old struggled to reach great heights until finding his rhythm across the third and fourth sets in a major confidence boost.

Norrie, a former No.8, was the last Brit in the draw as Zverev now sets his sights on playing 18th seed Francisco Cerundolo, who beat 13th seed Andrey Rublev in straight-sets. ■