Russian 19th seed Ekaterina Makarova knocked world number five German Angelique Kerber out of the Australian Open on her way into the quarter-finals on Sunday.
Makarova, who also made the last eight in 2012, came out on top of a tough battle 7-5, 6-4 and will play either second seed Maria Sharapova or the unseeded Kirsten Flipkens of Belgium for a place in the semi-finals.
"It's an unbelievable feeling. My team has done a great job and I'm so happy," said Makarova, who lost to Sharapova in the quarters last year.
Both players are left-handers and Makarova, 24, said it helped her read Kerber's game.
"As left-handers, we play the same shots, So I think I can read her a little bit."
It was a major disappointment for Kerber, who remains the only player in the current top 10 not to have made a Grand Slam final.
The two had met five times before with Kerber holding a 3-2 advantage and Makarova seemed determined to even up the tally, getting an early break when the German fired a forehand into the net to go 2-1 in front.
The big-serving Makarova easily held for 3-1 and it went with serve until the Russian ground out another break in the seventh to seemingly have Kerber on the ropes.
But the fifth seed immediately clawed back a game, held serve then forced a wild forehand from her opponent to break again and level up the set at 5-5.
Makarova responded and took the set with a searing backhand down the line.
The second set was a tight affair and went with serve up till the ninth game when Makarova got the break and served out the match.
She wants to meet Sharapova rather than Flipkens next, with last year's quarter-final defeat to avenge.
"I really want to play against Maria as I lost to her last year," she said. "I'm confident and like my game so think it will be really interesting."