Brisbane QLD, Australia, 9 April 2017 | AAP

Nick Kyrgios hopes he’s won over some of the hecklers who booed him off court at the Australian Open by sending his country through to the Davis Cup semi-finals in spectacular style.

Kyrgios won 7-6 (7-4) 6-3 6-4 against Sam Querrey to give Australia an unbeatable lead in the World Group quarter-final tie against the United States in Brisbane.

It is just the second time in the last 11 years Australia have made this stage of the competition, with a trip to Belgium or a home semi-final tie against Italy to come in September.

And it caps off a remarkable few months for the 21-year-old, who has emerged from a dark period following his second-round Australian Open meltdown against Andreas Seppi as one of the form players of world tennis.

“I got booed off the court at the Australian Open. And honestly, I don’t know why,” Kyrgios said.

“I lost in five sets and I gave my best effort there.

“It was tough. I wasn’t in a good place but I guess the one thing that fixes that is wins – getting out there and delivering.

“That’s what I’ve been doing and I’ve been doing it the right way.

“I thought (the crowd) really embraced me this time. I got two big wins and it’s hard not to like.”

Kyrgios did not even drop a set in his two matches at Pat Rafter Arena and stayed focused through many moments where previously his concentration lapsed.

“I’m going out there and playing the game how it’s supposed to be played, and I’m playing hard,” he said.

“I haven’t been going back to the hotel hating the game or trying to just get through every day. I’m trying to get better every day, and it’s a massive difference.

“I just feel like I’m becoming a bit more of a professional.”

US captain Jim Courier threw another curve ball by sending world No.25 Querrey onto Pat Rafter Arena instead of No.15 Jack Sock, who was originally slated to face Kyrgios.

Querrey had prevailed in his last meeting with Kyrgios in the semi-finals of February’s Mexican Open and has the same type of power-serving style as the lanky John Isner, who initially troubled the 21-year-old on Friday.

But after a nervy start, Kyrgios produced another commanding performance and showed more signs of his new found ability to produce under pressure.

He broke Querrey twice after the American led 4-1 as he attempted a comeback in the third set.

Then he wrapped up the two-hour victory with the last of his 21 aces, comfortably outserving Querrey, who hit only eight.

The tie finished 3-2 in Australia’s favour after Isner defeated Sam Groth in the final rubber.

Australia has not made the final of the Davis Cup since the last time they won it in 2003.