Novak Djokovic's wait for a 100th ATP singles title continues after he exited the Monte Carlo Masters in a "horrible" straight-set opening loss to Alejandro Tabilo.

Djokovic, a two-time winner of the event, made 29 unforced errors compared to his 18 winners in a subdued start to the 37-year-old's clay-court season, resulting in a 6-3 6-4 defeat.

The record 24-time men's major champion had won the last 10 matches he had contested on clay - including his run to Olympic gold in July.

But Chilean Tabilo, who beat Djokovic on the surface at the Italian Open 11 months ago, replicated that surprise victory to reach the third round.

"I expected myself at least to have put in a decent performance. Not like this, it was horrible," Serbia's Djokovic said.

"I did not have high expectations. I knew I'm going to have a tough opponent, and I knew I'm going to probably play pretty bad. But this bad, I didn't expect.

"I was hoping it was not going to happen, but it was quite a high probability I'm going to play this way.

"A horrible feeling to play this way, just sorry for all the people that have to witness this."

Earlier on Wednesday, Carlos Alcaraz rallied to a comeback victory over Francisco Cerundolo in the 21-year-old's first clay match of the season.

Spanish world number three Alcaraz was unable to match Argentine Cerundolo in the first set but dominated thereafter, winning 12 of the last 13 games for a 3-6 6-0 6-1 victory.

Norwegian fourth seed Casper Ruud beat Spain's Roberto Bautista Agut 6-2 6-1 to reach the third round, while Russian seventh seed Andrey Rublev overcame Frenchman Gael Monfils 6-4 7-6 (7-2).

Australian eighth seed Alex de Minaur came from behind to defeat Czech Tomas Machac, while Russian ninth seed Daniil Medvedev beat Alexandre Muller of France, also in three sets.

Great Britain's Jack Draper is back in action on Thursday, when the Indian Wells champion faces Spain's Alejandro Davidovich Fokina for a quarter-final place.

Djokovic's wait for century goes on

Djokovic is aiming to become only the third man in the Open era - after Jimmy Connors and Roger Federer - to win 100 Tour-level titles, having reached 99 by completing a career 'Golden Slam' at the Paris 2024 Olympics.

But, after being stunned by Czech teenager Jakub Mensik in the Miami Open final in his previous attempt at reaching the landmark, that wait goes on for Djokovic.

Making his 18th appearance in Monte Carlo, the 2013 and 2015 champion made the perfect start by breaking Tabilo's serve in the opening game.

But world number 32 Tabilo once again had the measure of the former world number one, against whom he has now achieved the two biggest wins of his career.

The 27-year-old produced an excellent response following his early setback, twice breaking an out-of-sorts Djokovic to turn the first set around.

Tabilo then struck what proved the decisive blow in the third game of set two, with Djokovic conceding on a second break point after inviting pressure with costly errors.

The Serb attempted to hang on, but Tabilo saved two break points to move within one game of victory before sealing it on his second match point.

Set to face Bulgarian 15th seed Grigor Dimitrov next, Tabilo said: "It has been a tough year, so a little bit of the nerves were there.

"I remembered last time what I did well, and thankfully, I served well today, and it helped me a lot. It was an unreal match."

Alcaraz gets up and running on clay

Competing for the first time since an early defeat at the Miami Open last month, Alcaraz earned his first career win in Monte Carlo to set up a third-round meeting with German qualifier Daniel Altmaier.

The reigning French Open champion raised his level in crucial moments early in the second set - seizing two of three break-point opportunities in Cerundolo's opening two service games to get back into the match.

Seeking the sixth ATP Masters 1,000 title of his career, Alcaraz continued to improve after completing his second-set whitewash, closing out victory with another five-game streak as Cerundolo's belief waned.

Beaten in his only previous match in Monte Carlo in 2022, Alcaraz said: "I didn't start well. I made a lot of mistakes.

"After the first set I knew I had to do something else, play more aggressively, play my own tennis."

Successful at Roland Garros and Olympic runner-up at the same venue last year, Alcaraz has won 13 of his last 14 matches on clay.

He added in his post-match interview that it was currently his favourite surface to play on, as he builds towards the defence of his French Open title.