Fourth seed Alexander Zverev and former world number one Novak Djokovic are among those who’ve been knocked out in their first matches at the BNP Paribas Open tennis tournament in Indian Wells.

Zverev was beaten by Portugal’s Joao Sousa in three sets.

In the women’s draw, another former world number one, Petra Kvitova, was beaten by unheralded American teenager Amanda Anisimova.

And French Open champion Jelena Ostapenko lost to Croatia’s Petra Martic in one of the biggest tennis tournaments outside the Grand Slams.

Djokovic is struggling to make his way back from a long term injury.  He’s had surgery on his right elbow this year, following his comeback at the Australian Open after a 6-month lay-off.

But he looked a shadow of his former self against Taro Daniel, the young Japanese player ranked 109 in the world.

He lost the first set on a tie-break, but managed to come back to win the 2nd. The third he lost 6-1, in a performance that puzzled many.

Former player Jim Courier said it looked like his body was healed, but not yet his head or his heart…

Djokovic says:”For me it felt like the first match I have ever played on the tour, very weird, I mean I just completely lost rhythm, everything, just struggled. Also a little bit with the health the last couple of weeks but yeah it was just, I was grateful to be out on the court after surgery that quickly but at the same time just didn’t feel good at all.”

 But there were no such problems for the current world number one.

Roger Federer’s match against Argentina’s Federico Delbonis had been interrupted by rain on Saturday night. He admitted that wasn’t ideal, but he wasted no time, winning the match 6-3 7-6.

Federer cannot be toppled off the top of the rankings if he reaches the semi-finals in Indian Wells.