Janik Sinner's anticipated rise to world No.1 was officialised on Monday when the ATP released its new rankings, making him the first Italian ever to hold the top spot.

"In Roland Garros, knowing all the Spanish players who have won this tournament and be able to put my name on that amazing list is something unbelievable," Alcaraz told reporters.

he injury, sustained in his fourth-round win over Francisco Cerundolo, ended the Serb's quest to win a record-extending 25th Grand Slam trophy and will result in him losing his top ranking to Italian Jannik Sinner on Monday.

Jannik Sinner took an unexpected path to the world number one ranking on Tuesday after Novak Djokovic's French Open withdrawal but the youngster said it was the culmination of years of hard work and represented a proud moment for Italy.

"Due to a torn medial meniscus in his right knee (discovered during an MRI scan performed today), Novak Djokovic... has been forced to withdraw from the Roland Garros tournament," organisers said in a statement.

The Serbian pulled off another astonishing escape as he reached a 15th consecutive French Open quarter-final.

The 24-time Grand Slam title winner made the last 16 by defeating Italy's Lorenzo Musetti in a bruising five-set epic which concluded at 3:07 am Sunday.

His four-hour 29-minute victory also allowed the 37-year-old world number one to equal Roger Federer's record of 369 Grand Slam match wins.

Novak Djokovic can equal Roger Federer's record for Grand Slam match wins by beating Lorenzo Musetti at the French Open on Saturday.

Djokovic, chasing a fourth title at Roland Garros and record 25th Grand Slam triumph, came through against 142nd-ranked French opponent Pierre-Hugues Herbert 6-4, 7-6 (7/3), 6-4.

World number one Novak Djokovic admitted he was "worried" about his French Open title defence after falling to 44th-ranked Czech Tomas Machac in the Geneva semi-finals on Friday.

Djokovic took a wild card to play in Geneva in a bid to rescue an alarming dip in form ahead of Roland-Garros next week.

Novak Djokovic celebrated his 37th birthday on Wednesday with the 1,100th win of his career as he gears up for his French Open title defence, progressing to the Geneva quarterfinals.

He said if Nadal was in the French Open draw, he could not be ruled out, despite his injury problems and growing competition from a younger generation.

Djokovic said that his subdued performance on a court where he has won six titles might have been due to the blow suffered while greeting fans on Friday night.

Djokovic's bid for a record-extending 41st Masters 1000 title was ended in just over an hour by Chilean Tabilo, who is ranked 32nd in the world but was hugely impressive and claimed his first win over a top-10 opponent.

Novak Djokovic was left in agony after being struck with a hard plastic water bottle as he left the court following his 6-3, 6-1 win over France's Corentin Moutet at the Rome Open which advanced him to the third round on Friday.

World number one Novak Djokovic said he believes he will be in top form for the French Open and hopes to prove that at the Italian Open which started on Wednesday.

Last month, the Serb ended a five-year partnership with coach Goran Ivanisevic.

The Italian world number two can come within touching distance of the top-ranked Djokovic in the standings should he triumph in Madrid this fortnight and he arrives in the Spanish capital brimming with confidence and carrying an impressive 25-2 win-loss record for the season.