(CNN) -- Second seed Serena Williams was made to battle all the way before reaching the second round of the French Open at a cold and windy Roland Garros on Tuesday.
Williams cannot hide her relief after finally securing victory over Klara Zakopalova at Roland Garros.
Williams, the champion here in 2002, secured her first clay-court victory in 12 months after edging past Klara Zakopalova 6-3 6-7 6-4, as the searing heat of the first two days of action was replaced by altogether cooler conditions.
It was the American's first claycourt win since the second round here last year -- and avenged her surprise defeat to the Czech in the first round in Marbella in April, although she spurned a remarkable eight match points before sealing a hard-fought victory.
"I think I played a very good match and I think Serena will be playing better and better, so it was my best chance to beat her," a disappointed Zakopalova told reporters after the match.
Williams, who has never lost to an opponent ranked 100 or lower since her first professional match in 1995, joins sister Venus in round two, where she will play Virginia Ruano Pascual of Spain.
There were no such trials and tribulations for fifth seed Jelena Jankovic, who shrugged aside a two-hour rain delay before getting past another Czech, Petra Cetkovska, 6-2 6-3.
"I managed to finish the job in two sets, which I'm happy about," the Serb told Press Association Sport. "I'm trying to make baby steps forward -- that is my goal at the moment."
Meanwhile, there was an emotional return to Roland Garros, after a five-year absence, for unseeded Australian Jelena Dokic.
The 26-year-old, whose career had spiralled away prior to her amazing run to the Australian Open quarterfinals this year, beat Slovenia's Karolina Sprem 3-6 6-1 6-2 -- her first victory at Roland Garros since she reached the second round in 2003.
Dokic, who reached the quarterfinals in 2002, will now face Russian fourth seed Elena Dementieva, who eased past South African Chanelle Scheepers 6-4 6-3, for a place in the last 32.
Seventh seed Svetlana Kuznetsova also progressed with a 6-1 6-4 win over France's Claire Feuerstein, on a day of no shock results.