An inspired Nick Kyrgios dug deep into his tennis bag of tricks on Friday to hammer Pablo Carreno Busta 6-4, 6-2 for a place in the Halle grass court semi-finals.

The Australian, who also reached the final four last weekend in Stuttgart, treated the crowd to an assortment of 'tweeners', behind-the-leg flick returns and an underarm serve to baffle his Spanish opponent in 69 minutes.

Kyrgios hit 13 aces and broke three times as he gains momentum on grass as a serious Wimbledon outside threat. 

Kyrgios said he played a standout match against Carreno Busta in their first meeting since 2016.

"I've had some good runs in my career, but I'm really pleased with this performance," the world number 65 said.

"He's Spanish but plays well on all surfaces and hits a flat ball - he's an all-court player.

"I knew I had to be locked in from the back (of the court), I played really well today."

Kyrgios won the sixth game of the opening set with a tiny flick from behind his legs on a return, causing Carreno Busta to sail a return long.

The Australian wild card, who lost in the Stuttgart semis last week to Andy Murray, also played an underarm serve in the sixth game of the second set as he closed in on victory. 

"Tennis has been so straight for so long. All I'm doing is an underarm serve. It was not much, but the crowd went crazy," he said.

"They are so used to watching the same thing every time. When someone like me comes and does things differently, that's all it takes."

Top seed Daniil Medvedev had another easy passage as he defeated Spain's Roberto Bautista Agut 6-2, 6-4.

Medvedev now faces German Oscar Otte, a 4-6, 7-6 (7/5), 6-4 winner over eighth seed Karen Khachanov