With just 10 days to go until the start of Wimbledon (Monday 1-Sunday 14 July), the world's top tennis players have had mixed results.

Top-ranked Italian Sinner, a semi-finalist at last year's Wimbledon, beat 45th-ranked Hungarian Fabian Marozsan 6-4, 6-7 (4/7), 6-3 to set up a clash with 41st-ranked German Jan-Lennard Struff, who beat Stefanos Tsitsipas 6-4, 6-4 in just 67 minutes.

With a packed Centre Court on hand to see the first Italian ever top the world rankings, Sinner broke the Hungarian's second service game.

Almost at the same time, his fierce rival Alcaraz, who beat Sinnerin the semi-finals of Roland Garros a few weeks ago, lost in straight sets 7-6 (7/3), 6-3 to local hero Jack Draper (31st).

After taking the first set in a tie-break, Draper, who won his first grass court title in Stuttgart last week, broke for a 5-2 lead in the sixth game of the second set to see off Alcaraz. The Briton is aiming to become the first British men's singles champion at Queen's since Andy Murray won his fifth title at the event in 2016.

Following his defeat, the Spaniard was particularly critical of the new serve-clock rule, which he described as "madness" and "bad for the player". Under the new rule, the clock starts ticking as soon as the point ends, rather than when the umpire calls it, giving players less time to execute their serve - a crucial offensive weapon in today's tennis for dominating space and strategy.

"I know I didn't play well, I didn't move well," admitted the recent Roland Garros champion. "The best way to improve on grass is to play on grass. In Spain, where I live, there are not many grass courts where I can train," added the Murcian, who turned 21 last month.

Despite the defeat, the tournament will be played on the same surface where Alcaraz will defend his Wimbledon title in London.

Wimbledon champion Carlos Alcaraz said that losing is "part of life. You have to deal with it the best you can. After defeats you have to take the positives and of course the negatives to improve for the next tournament. I have to give credit to Jack. I thought he played really good tennis today.

Alcaraz, who will defend his title on 1 July at the All England Club in the British capital, just a few miles from Queen's, said he would stay in London to prepare.

"I think the best way to improve on grass is to stay here, train with the players, do good physical things on grass and movement, very specific things," said Alcaraz when asked if he would return to Spain before Wimbledon.

"In Spain or in my country, we don't have grass courts or really good places to practice," he agreed.