World number one Simona Hale p breezed through her WTA fourth round match with a 7-5, 6-1 victory over China’s Wang Qiang.
Halep, who is one of two former champions left in the draw, is now 17-1 on the season having already won a title in both singles and doubles at Shenzhen, China.
Halep advances to the quarter-finals where she will face unseeded Petra Martic of Croatia who beat Czech Marketa Vondrousova 6-3, 7-6 (7/4).
Halep called for a timeout in the first set so her coach Darren Cahill could come down to the court to discuss strategy.
“It was really important, because he just told me what I have to do. I knew that I had to change something, but I didn’t realize what it was exactly,” she said.
“So it was a good chat. I did exactly what he said after that.”
In other women’s matches, eighth seeded Venus Williams survived a stern test from Latvia’s Anastasija Sevastova to win 7-6 (8/6), 6-4 and fifth-seeded Karolina Pliskova beat Amanda Anisimova of the USA 6-1, 7-6 (7/2).
Halep needed just 76 minutes on the main stadium court to dispatch Wang as she won 64 percent of her first-serve points and broke Wang’s serve seven times.
Halep said she is happy with the way she is playing at this stage in the tournament.
“I am confident. I am feeling the game,” she said.
Halep and second seed Caroline Wozniacki have taken turns being No. 1 this year with Wozniacki grabbing it after beating Halep in three sets in the Australian Open final and Halep winning it back just prior to Indian Wells.
Halep can hold onto the top ranking by reaching the final here.
Halep won this event in 2015 and Wozniacki won it in 2011.
Wang was the last Chinese player standing in the California desert, having achieved a career best result in Indian Wells by reaching the round of 16.
Tuesday’s quick victory came two days after Halep needed over two hours to eliminate American teenager Caroline Dolehide 1-6, 7-6 (7/3), 6-2.
“The previous match was really tough for my body,” said Halep, who missed some time this year with a right foot injury.
“I stayed so many weeks off with injury and now coming back, so I was a little bit tired.
“I missed too many shots in the first set. And then I just got the idea of what I have to do to play against her, and it was much easier.”