Rafael Nadal's bid for an historic eighth French Open title was almost spectacularly derailed on Monday by big-hitting German Daniel Brands.
Defending champion Nadal dropped the opening set of a Grand Slam for the first time in his career before he prevailed 4-6, 7-6 (7/4), 6-4, 6-3 against a player who had lost all four of his previous matches in Paris.
The Spaniard, who before this year had only lost once in 53 matches at Roland Garros, came into the tournament having won six titles in eight finals since he returned from a seventh-month injury lay-off.
But the 26-year-old was caught cold by world number 59 Brands who unleashed a fearless barrage of attacks off both sides to leave the third seed reeling.
It was almost a carbon copy of the tactics employed by Robin Soderling, the only man to beat Nadal in Paris four years ago, and Lukas Rosol, who dumped the Spaniard out of Wimbledon last year.
Brands even led 3/0 in the second set tie-breaker as he appeared poised to deliver the first defeat of a men's champion in the opening round in tournament history.
But Nadal eventually found his rhythm to steady the ship as the 25-year-old German eventually ran out of firepower.
"He was playing unbelievable. I tried to find my game and tried to resist his fantastic shots," said Nadal, who will face Martin Klizan of Slovakia for a place in the last 32
"He played a great match and put me in a tricky situation."
Brands admitted that a missed simple volley in the second set tie-breaker which would have given him a 4/2 lead had been crucial.
"I played my best tennis today, but the tie-break was the turning point. After that I lost concentration and he was just better than me after the second set," said the German.
Also going through to the second round was French sixth seed Jo-Wilfried Tsonga who is looking to become the first home player to win the men's title since Yannick Noah in 1983.
He started confidently enough with a 6-2, 6-2, 6-3 win over Aljaz Bedene of Slovenia.
"My groundstrokes pretty solid from the baseline. I played pretty well, but my service was really low quality," said Tsonga.
Maria Sharapova, the second seed and defending women's champion, begins her 2013 campaign later Monday against Taiwan's Hsieh Su-Wei.
The Russian opened her claycourt season with a title win in Stuttgart, but was then easily beaten by Serena Williams in Madrid before pulling out of the Rome quarter-finals with an illness.
She currently stands 2-13 against Williams and has not beaten the American since 2004, the year she won Wimbledon.
Li Na, the 2011 champion, and Polish fourth seed Agnieszka Radwanska were early winners.
Sixth seeded Chinese star Li was a 6-3, 6-4 victor over Anabel Medina Garrigues, the experienced Spaniard playing in her 38th consecutive Grand Slam event.
Li, who had lost all of her three previous meetings on clay against Garrigues, goes on to face Bethanie Mattek-Sands of the United States.
Radwanska, who has never got beyond the last 16 in Paris, breezed past Israel's Shahar Peer 6-1, 6-1 and will face America's Mallory Burdette in the next round.
She is scheduled to face younger sister Urszula, who knocked out Venus Williams on Sunday, in the third round.
The Pole, last year's Wimbledon runner-up, came into Paris nursing a shoulder injury which forced her to withdraw from Brussels last week and contributed to second round exits in Madrid and Rome.
But Radwanska, with her hair now dyed blonde just like her sister, said she is fit enough to last the distance at Roland Garros.
"Well, it's up and down, but definitely it's a little bit worse on clay," she said. "I think I'm used to the pain. I'm ready to go and I'm 100% fit."
Other early winners Monday included Japan's 13th seed Kei Nishikori, Tommy Robredo, the Spanish 32nd seed and Australian 18-year-old Nick Kyrgios who beat Radek Stepanek, 16 years his senior, on his Grand Slam debut.
In women's action, Danish 10th seed Caroline Wozniacki saw off British hope Laura Robson 6-3, 6-2.
There was also a first ever win in the majors for Slovakian 20-year-old Zuzana Kucova who defeated German 24th seed Julia Goerges 7-6 (10/8), 6-0.
Qualifier Kucova is ranked at 1,152 in the world and had lost in qualifying on 21 occasions before making her breakthrough this week.