Tennis: Nick Kyrgios smashes racket, serves underarm in first round Madrid Open loss

Another episode in the strange and controversial career of Australia's Nick Kyrgios unfolded in the Madrid Open as he slipped to a 7-6, 6-4 first-round defeat against Germany's Jan-Lennard Struff.

Kyrgios was up to his usual tricks as he attempted numerous underarm serves and eventually smashed one of his rackets in the opening set.

The 24-year-old also ignored the umpire and his opponent at the coin toss when he bent down to tie his laces.

While the first set was close on the scoreboard, Struff dominated play with Kyrgios winning just three points on his opponent's serve across six games and a tiebreaker.

It looked like things would turn around as Kyrgios capitalised on a double fault and some unforced errors by world number 48 Struff as he claimed a break in the opening game of the second set.

But the advantage wasn't to last.

Struff ultimately levelled at 2-2, games staying on serve until he broke Kyrgios comfortably at 5-4 to take the match.

The German had been in recent good touch on clay with a quarter-final run at the Barcelona Open where he enjoyed wins over David Goffin and Stefanos Tsitsipas before going down to Rafael Nadal.

It was another mixed bag from the world number 34 who served well on occasion but bombed out with all three underarm deliveries and relied too heavily on drop shots to win some cheap points.

His one outburst occurred after Struff won a point to serve for the first set, Kyrgios breaking his racquet in frustration and earning a warning.

Kyrgios had been playing his first match since the Miami Open in March when he lost to Borna Coric in the round of 16.

Unless he performs better in Rome, he'll struggle to break into the top 32 and earn a seeding at the French Open which starts on May 26.

AAP.