Halep’s recently hired coach, Wim Fissette, credits her improved play to increased aggressiveness. Fissette, a Belgian who worked with Kim Clijsters during her successful comeback, said Halep told him that before her results improved, she was scared to play assertively.

“She told me she put too much pressure on herself and, therefore, she was always starting with the plan of making no mistakes, no unforced errors,” Fissette said. “The focus was too much on that, and she was too defensive. At one moment, she really told herself to be more offensive, to play more aggressive. And that’s what she did, and she gained confidence by winning matches and she became more and more aggressive.”

Third-ranked Agnieszka Radwanska, who ousted Halep in the semifinals on Friday at the BNP Paribas Open here in this desert resort town, had lost to Halep in the semifinals at Doha, Qatar, last month, where Halep won her biggest title to date. Radwanska took note of her opponent’s prowess on offense and defense.

“She was playing unbelievable that day,” Radwanska said. “Well, I didn’t play bad. I really didn’t. I wasn’t even mad after the match because I was really doing everything right but just everything was coming back, and most of the time, it was for winners.”

Halep grew up in Constanta on the Black Sea and began to play when she was 4, following in her older brother’s footsteps. She found success in the junior ranks, winning the junior title at the French Open when she was 16.

Halep credits much of her success to her first childhood coach, Ene Nicusor, who, she said, taught her discipline and professionalism.

As Halep and her success continue to arrive ahead of schedule, her manager, the 1978 French Open women’s champion Virginia Ruzici, says Halep can emerge as one of the best clay-court players in an era in which few of the top contenders have shown a natural affinity for the surface.

“Being a very good, typical clay-court player with movement, perfect movement on clay, sliding, I think she has a good chance,” Ruzici said by phone from her home in Paris. “I don’t know if it’s going to happen this year, or if it is going to happen in the next two years or so, but I really think she has a good chance to really win a Grand Slam tournament.”