Halep breezes into Indian Wells semi-finals
Romania's Simona Halep, pictured here returning a ball to France's Alize Cornet in the second day of the Dubai Duty Free Tennis Championships in Dubai, on February 18, 2014 - by Marwan Naamani
Halep, the sixth seed, needed precisely one hour to get past Dellacqua, saving all five break points she faced and breaking the 78th-ranked Aussie twice in each set.
Halep next faces either former world number one Jelena Jankovic, the seventh seed, or second-seeded Agnieszka Radwanska, who were meeting under the floodlights at the Indian Wells Tennis Garden on Wednesday night.
Top seed Li Na, the reigning Australian Open champion and world number two, will take on Slovakian Dominika Cibulkova in a rematch of the Australian Open final in a quarter-final clash on Thursday.
The winner of that match will face either 17th-seeded American Sloane Stephens or Italian Flavia Pennetta, the 20th seed.
Halep, 22, has won seven WTA tour titles, six of them in her breakout 2013 campaign and at Doha this year.
But the world number seven is through to the semi-finals of one of the WTA's elite Premier Mandatory tournaments for the first time.
"I was moving really well today," said Halep, who had said she felt sluggish against rising Canadian star Eugenie Bouchard in her fourth round match on Tuesday.
"I had no pressure, and I was more relaxed than yesterday. I tried my best. My game is to be aggressive, to hit the balls, and I did really well today."
Halep said it wasn't Dellacqua's lower ranking that took the pressure off, but the confidence of having two good wins behind her, against Bouchard and Czech Lucie Safarova.
"I won two important matches before. I said that if I'm in quarter-finals I have just to enjoy to play what I can. So I tried and everything was going very well."
After her spectacular 2013 season, Halep confirmed her class with a sparkling run to the Qatar Open last month.
She breezed past fourth-seeded Italian Sara Errani before beating former Wimbledon finalist Radwanska in the semi-finals and downing Angelique Kerber in the title match.
Her success has made her a celebrity in her native Romania -- something the player who calls herself "a normal girl" is still getting used to.
"I was surprised when I wanted to park and I didn't have space. Someone came and put me in front of the hotel.
"You can park here, he told me. Everybody knows me now."