Victoria Azarenka's off-court problems have hampered her comeback after giving birth to her son in December 2016, but her Miami Open run is restoring her confidence about remaining competitive.

Azarenka returned from 13 months off last June and made a promising start to life back on the WTA Tour as she reached the fourth round at Wimbledon.

However, since exiting the grass-court grand slam to Simona Halep she played only one tournament before heading to Miami.

A custody battle over her son Leo meant Azarenka was forced to pull out of the Fed Cup final, Australian and US Opens as she needed to remain in California.

The 28-year-old eventually returned at Indian Wells this year but was beaten in the second round by Sloane Stephens. However, she will get a shot at revenge in Florida.

Despite her lack of competitive action, Azarenka has looked sharp and impressed with victories over Madison Keys, Agnieszka Radwanska and Karolina Pliskova.

Her 7-5 6-3 win over former world number one Pliskova on Tuesday set up a semi-final with Stephens, and Azarenka is confident she can go all the way and lift a fourth Miami crown.

"It feels really good," Azarenka told a media conference. "Before the match I said it was going to be a great test for me to see where my game is at. I think it gives myself a lot of positive things to continue to work on."

"And seeing the progress that I made throughout this whole tournament, playing first round to playing a top-five player, I made a pretty good gap of improvement. I want to continue to go down this path."

"I think I'm not a bad player, so I know how to win matches. I have a lot of experience. For me it's important to stay healthy, to keep improving and to be able to play."

She added: "The possibility of winning [the title] is always in my head. That's why I play. I don't come to a tournament just to play. But I'm always taking one match at a time."