Aryna Sabalenka has taken first blood for Belarus in a rollercoaster Fed Cup semi-final opener against Samantha Stosur in Brisbane.

The 20-year-old prevailed 7-5 5-7 6-3 at Pat Rafter Arena in a nervy contest that lasted nearly three hours, featured 17 breaks of serve and as many momentum swings.

Stosur fought from a set and break down but the world No.10’s power game eventually proved too much ahead of Ashleigh Barty’s battle with Victoria Azarenka on Saturday afternoon.

Sabalenka was destructive on two fronts, mixing unbeatable tennis with regular unforced errors while Stosur did well to match her power from the back of the court.

The Belarusian coupled 15 double faults with 37 winners across the contest to ensure there was always pressure on her serve.

Every time she looked to seize control Stosur would find a way back in, with five consecutive breaks of Sabalenka’s serve in the second set helping the Australian get back on level terms.

Stosur matched Sabalenka from the back of the court for the most part but landed only 56 per cent of first serves and won just 26 per cent of points on her second serve.

Sabalenka lifted a gear in the third set and a series of brutal forehand winners landed her the crucial break as the rowdy crowd armed with horns and a drum rode every point.

The visitors should have sealed it with Stosur serving at 2-5, Sabalenka spraying a wild backhand from on top of the net with the court wide open on match point

Stosur held serve but Sabalenka made no mistake in the next game to give Belarus the early running.