Dimitrov tumbles out in Paris
Ivo Karlovic won his first French Open match in seven years to send Grigor Dimitrov crashing out in the first round.
Dimitrov has been one of the stars of the season and, after reaching his first grand slam quarter-final in Australia, he had expected a better showing here.
But 6ft 11in Karlovic is always a man players like to avoid and he has been showing rare good form on clay having reached the final in Dusseldorf last week.
His record at Roland Garros leaves something to be desired, Karlovic having won only two matches in Paris in his career and none since 2007.
But his forehand was on fire as well as his serve and he ousted 11th seed Dimitrov 6-4 7-5 7-6 (7/4), clinching victory with his 22nd ace.
Dimitrov, who followed top-10 duo Stan Wawrinka and Kei Nishikori out of the tournament, said: "It's never easy to play against Ivo.
"Of course, it's a big disappointment for me, losing first round of the tournament. I like my chances here. I've been playing good tennis on the clay courts, so I don't want to be too disappointed. It happened.
"I just couldn't find the rhythm, and I couldn't achieve any of the little opportunities that I had in the match. So it's something to obviously learn from, but in a way it was one of those days that you can't control anything."
Fifth seed David Ferrer made his return to Court Philippe Chatrier a year after reaching his first grand slam final and was very comfortable in a 6-4 6-3 6-1 win over Igor Sijsling.
Twelfth seed Richard Gasquet, who had not played a match since March because of a back injury, eased his way into the tournament with a 6-2 6-1 7-5 victory over Bernard Tomic.
The Australian, who has won just one match since hip surgery, is again being accompanied to tournaments by his father John following the end of his ATP ban.
Tomic Sr was prevented from gaining accreditation at tournaments for a year after being found guilty of assaulting his son's former hitting partner, Thomas Drouet.
The ban expired earlier this month, and Tomic said: "It's good to have him back. It's been one year and it's been difficult for me.
"Support is different having your dad there, someone that grew up with you your whole life and knows you best.
"We started a long journey together, my dad and myself. We didn't have anything, so my dad is everything to me. He knows everything about me. It's stupid for me to lose someone like that in my life that brought me to the level where I was at."
French favourite Gael Monfils gave the crowd on Chatrier what they wanted with a 6-2 4-6 6-4 6-2 victory over Victor Hanescu but Michael Llodra has made his last appearance at Roland Garros as a singles player.
The 34-year-old, who will retire at the end of the season, lost 6-2 7-6 (7/4) 7-6 (7/3) to 24th seed Fernando Verdasco.
Two seeds exited through injury, Tommy Haas and Nicolas Almagro both quitting mid match, while Lleyton Hewitt was beaten 3-6 6-2 6-1 6-4 by Argentina's Carlos Berlocq.
The second round begins on Wednesday, with Roger Federer following Rafael Nadal out to Suzanne Lenglen for his match against Diego Schwartzman while Novak Djokovic takes on France's Jeremy Chardy on Chatrier.