Australia's Nick Kyrgios has brushed aside the challenge of seeded Italian Fabio Fognini to move into the last 16 of the Miami Open, where he'll be joined by the other half of the Special Ks, Thanasi Kokkinakis.

Wild card Kyrgios beat his veteran opponent, ranked 34th in the world, 6-2, 6-4 in 61 minutes.

The Italian looked to be out of sorts in the opening set, struggling with his movement. Kyrgios took full advantage, taking the set in 28 minutes, breaking in the opening game and again in the seventh.

The Australian dropped just five points on first serve in the set.

Loading

However, Fognini rallied in the second set, looking uncomfortable between points, but perfectly fit during play.

The Australian, eight years younger at 26, but ranked 102nd, looked frustrated at this inconsistency as the match went with serve to 4-4.

Kyrgios then stepped up a level-winning eight points off the reel to break, then serve out for victory. He will next play Jannik Sinner, the world number 11, or Pablo Carreno Busta.

His strong form in Miami follows his run to the quarter-finals at Indian Wells, where he lost to eventual finalist Rafael Nadal. 

British commentator and former Wimbledon finalist Tim Henman said of Kyrgios: "It was a really great performance, not only was his tennis of a really high standard, I thought mentally he kept his composure really well.

Kokkinakis, meanwhile, needed almost three hours to shake off American Denis Kudla 7-6 (5) 4-6 7-6 (4).

He stood three points from losing the marathon encounter before pulling out an important win that set up a showdown with German second seed Alexander Zverev.

Win or lose their next matches, Kyrgios and Kokkinakis are now assured of both being in the world's top 100 again for the first time since August of 2016.

"It's awesome to see," Kyrgios said of Kokkinakis' stunning renaissance following years of endless injuries.

"I see him in the locker room and having lunch and just see a happier person. I don't really care about results and all that, I know what he's capable of, I've grown up with him.

"I saw him go through that. Just seeing him happy again and being at these big events and winning, that's all I care about. Not his results."

Earlier, Britain's Cameron Norrie beat Hugo Gaston, of France, 6-3, 7-5, to earn a last-16 meeting with Casper Ruud.

Loading

The in-form Ruud dispatched Alexander Bublik 6-3, 6-2 in less than an hour and had the best seat in the house when his Kazakh opponent produced a highlight-reel-worthy shot in the fifth game of the second set.

Bublik flipped his racquet over and tapped an overhead shot with the handle.

"You will be on Tennis TV like always," Ruud quipped to Bublik after the match.

AAP/Reuters