The world No.9 advanced to the third round of the Madrid Open for the first time with a 6-1 1-6 6-1 victory.

Locked up a set apiece, Barty took an early break with an unbelievable drop shot that left Collins with no chance.

While the 23-year-old blasted 18 winners and fired five aces, she had 19 unforced errors and only made 55 per cent of her first serves in this rollercoaster encounter. 

It took Barty just 24 minutes to close the opening set but Collins took the second in the same amount of time.

Collins had momentum on her side going into the deciding set but Barty reeled off three games in a row to put the 2019 Australian semi-finalist on the back foot.

While the American managed to halt the onslaught at 3-1, it was the only game she would see as Barty saw out the match for her 10th consecutive WTA singles win. 

Overall, she is undefeated in 12 matches across doubles and singles in both WTA events and the Fed Cup.

She now faces Yulia Putintseva, who beat Pauline Parmentier 6-4 4-6 6-3.