Alexandr Dolgopolov of Ukraine celebrates his victory over Robin Soderling of Sweden at the Australian Open tennis tournament in Melbourne January 24, 2011. [Photo/Agencies]

MELBOURNE - Ukrainian Alexandr Dolgopolov produced a stunning five-set upset over fourth seed Robin Soderling to reach the Australian Open quarter-finals on Monday.

The pony-tailed Dolgopolov completed a shock 1-6 6-3 6-1 4-6 6-2 win in Melbourne with a heavily whipped forehand to become only the second man from his country to reach the last eight of a grand slam.

Swede Soderling, French Open runner-up the past two years, took a medical timeout in the fourth set to treat blisters on his foot before going on to level a cliff-hanger fourth round match.

However, he was quickly staring down the barrel in the deciding set, Dolgopolov drilling another big forehand past the Swede to break for 3-1.

The 23-year-old was making only his fourth grand slam appearance but held his nerve to record his first win over a top 10 player and the biggest upset of the year's first major so far.