San Francisco Frontiers - Djokovic crashes to nervous Arnaldi in Madrid opener

The fourth-seeded Djokovic suffered a second consecutive opening defeat, he also exited in his opener against Alejandro Tabilo in Monte Carlo two weeks ago.

Arnaldi, ranked 44th in the world, recorded just the second top-five win of his career and scribbled 'OMG' on the camera lens after his landmark victory.

"At the start I was just trying to not s*** in my pants, to be honest," said the 24-year-old Arnaldi.

The athletic Arnaldi squandered a 2-0 lead early in the contest but pounced again in the eighth game, breaking the Djokovic serve. The Italian wrapped up the opening set in 48 minutes.

Djokovic, a three-time champion in Madrid, fired 20 unforced errors in the first frame and finished the contest with a total of 32.

"He's my idol, he's always been. I was just glad that I could play him because I never played him, I just practised once with him. So playing him on a stage like this was already a victory for me," said Arnaldi, who showcased an entertaining brand of all-court tennis.

"But, you know, he is not at his best right now, so I came on court to try to play my best tennis and win. It happened. So right now, I don't even know what to say."

Elsewhere, Lorenzo Musetti, playing his first match since reaching the biggest final of his career in Monte Carlo, moved past Argentina's Tomas Etcheverry 7-6 (7/3), 6-2 to book a third-round meeting with Stefanos Tsitsipas.

The talented Italian is on the cusp of making his top-10 debut, having entered the tournament at a career-high number 11.

Musetti admitted he is doing his best not to check the ATP live rankings website until he officially joins the top-10 club.

"This week, I don't want to look," said the 23-year-old, who moved up to number nine in the live rankings on Saturday.

Reigning Australian Open champion Madison Keys was broken while serving for her third-round victory at 5-4 in the second set against Anna Kalinskaya, but recovered to complete a 7-5, 7-6 (7/3) in one hour and 48 minutes.

The fifth-seeded Keys lost to Kalinskaya earlier this month in Charleston.

"I knew I had to raise my level after getting a bit of spanking last time," said Keys.

A semi-finalist in Madrid 12 months ago, Keys awaits her compatriot Emma Navarro or Croatia's Donna Vekic in the round of 16.

American fourth seed Coco Gauff eased past compatriot Ann Li 6-2, 6-3 to set up a last-16 clash with Swiss Olympic gold medallist Belinda Bencic.

Seventh-seeded teenager Mirra Andreeva continued her impressive form at WTA 1000 tournaments this season by storming into the fourth round with a 7-5, 6-3 performance against Polish 27th-seed Magdalena Frech.

The 17-year-old Russian, who won back-to-back titles in Dubai and Indian Wells, will take on Ukrainian qualifier Yulia Starodubtseva for a shot at reaching a second consecutive Madrid quarter-final.

G.Miller--SFF