INDIAN WELLS, CA, USA - No.1 seed Simona Halep put on a crescendo of a performance to book her place in her fourth BNP Paribas Open quarterfinal, with her trademark baseline intensity getting better and better over the course of a 7-5, 6-1 defeat of unseeded Wang Qiang.

The first meeting between the 26-year-olds saw both players focus on testing the other's baseline consistency throughout an evenly contested first set. The Chinese No.3 scored some early highlight reel points off both wings in the opening stages, but it was Halep who found an extra gear in the fifth game, hammering spectacular down-the-line winners off first the forehand and then the backhand en route to breaking for the first time.

The Romanian's aggression went awry immediately, though, with her forehand letting her down as cheap errors conceded the break back in the next game. Another two breaks followed, as both players' attempts to stay on top of rallies resulted in more errors; and then a pair of holds, with improved serving stabilising their games.

The World No.1 picked the eleventh game to move through the gears again, dominating with her forehand to break Wang's serve for the third time; and, though overcooked forehands and a fabulous backhand winner staved off three set points in the next game, Halep pulled out a timely service winner to close it out on her fourth.

Wang's disappointment at coming out on the losing end of a set of narrow margins manifested itself in a poor start to the second set. The World No.55 conceded her first service game to love, and lost 12 of the set's first 15 points as her backhand began to leak a plethora of errors.

Halep, by contrast, used her victory as a launching pad to go to a new level - and, this time, to stay there. Taking the ball earlier and earlier, there was little hesistancy about the 2015 Indian Wells champion's game now; the sheer impenetrable intensity of the high-octane rallies she forced Wang to engage in had the effect of smothering her opponent's game.

Trailing 0-3, the Chinese No.3 hustled gamely to retrieve one of the breaks, refusing to go gently into the desert afternoon in her first fourth-round appearance here. Indeed, the final four games provided the highest-quality tennis of the encounter from both players as Wang desperately continued to halt the Halep march to the finishing line.

It was in vain; though Wang, playing a World No.1 for the first time in her career, scored hits with determined counterpunching, her strokes would invariably break down first in their toe-to-toe rallies. In the final game, the Australian Open runner-up fought through three deuces before firing a 16th and final laser-like forehand winner down the line to set up match point. A 29th unforced error from Wang later, and Halep was through to her fourth Indian Wells quarterfinal in eight visits, where another unseeded player awaits in the form of Petra Martic.