Madrid - Wary top seed Novak Djokovic said on Monday he hoped that play this week on the untried blue clay laid down for the Madrid Masters will be injury-free as the controversial surface gets a test under battle conditions.
The world No 1 also fired a shot across the bow of the ATP, which agreed to the one-year experiment without informing players, a coup quietly pushed through without executive oversight by former boss Adam Helfant, who left at the end of 2011.
"The hope of all players is that we won't have injuries and have a decent week of tennis," said Djokovic, who skipped the ATP event in Belgrade last week after the death of his grandfather during the Monte Carlo Masters.
Serb Djokovic played through his emotional pain and reached the Monte Carlo final, where he was crushed by Rafael Nadal.
"The blue clay surface makes this year different," said the 2011 Madrid champion. "It is the first time in history. It will be interesting for everyone to see what happens.
"There is a certain difference compared to red clay, but we have it (blue) in front of us. I tried to prepare for it as well as I could. But it's the same for everyone."
Djokovic joined with Nadal in criticising ATP executives who didn't bother to consult with at least their top-shelf players.
"The only disappointing thing from a player standpoint is that it was decided without players agreeing to it," said the Serb. "Players should be agreeing to the change - there should be some value in what they say.
"I'm not blaming the tournament, it is fighting for its own interests. But the ATP should have done a better job on player rights in protecting what the players want."
The proposal from larger-than-life billionaire Madrid impresario Ion Tiriac is on a one-year trial, with the event saying its purpose is to help spectators see the yellow ball more clearly on the blue surface.
On court, women's holder Petra Kvitova kick-started her title defence with a 6-2, 6-3 defeat of New Zealand's Marina Erakovic.
The third-seeded Wimbledon champion, who defeated Victoria Azarenka in straight sets to lift the 2011 trophy, went through into the second round in 67 minutes, firing five acres and producing 28 winners.
Erakovic, the No 39 who has lifted her game in recent months with a Memphis final and semi-final showing last week on clay in Budapest, was broken five times.
American Serena Williams, the former No 1 now seeded ninth, started out with a victory over Russian Elena Vesnina 6-3, 6-1 which began at the early hour of 11:00.
"I always hate the early starts," said the 30-year-old Williams.
The 30-year-old has picked up her pace in recent months, reaching a Miami quarter-final, winning the title in Charleston and travelling to the Ukraine for Fed Cup to ensure London Olympics eligibility.
Elsewhere, Czech Andrea Hlavackova out Australian Anastasia Rodionova 6-1, 6-4 while Lucie Hradecka beat China's Peng Shuai 6-4, 5-7, 6-4.
In men's play, Russian Mikhail Youzhny defeated local wild card Javier Marti 6-3, 6-2 and Serb Viktor Troicki out American Donald Young 6-1, 4-6, 6-1.
Results from the ATP and WTA Madrid Open on Monday (x denotes seeding):Women
Petra Kvitova (CZE x3) bt Marina Erakovic (NZL) 6-2, 6-3
Serena Williams (USA x9) bt Elena Vesnina (RUS) 6-3, 6-1
Andrea Hlavackova (CZE) bt Anastasia Rodionova (AUS) 6-1, 6-4
Ekaterina Makarova (RUS) bt Galina Voskoboeva (KAZ) 6-2, 7-6 (7/3)
Lucie Hradecka (CZE) bt Peng Shuai (CHN) 6-4, 5-7, 6-4
Lucie Safarova (CZE) bt Kaia Kanepi (EST) 6-4, 6-4
Carla Suarez Navarro (ESP) bt Jelena Jankovic (SRB x15) 4-6, 7-6 (7/5), 6-4
Sara Errani (ITA) bt Chanelle Scheepers (RSA) 4-6, 6-2, 6-3
Petra Cetkovska (CZE) bt Lourdes Dominguez Lino (ESP) 6-4, 7-5
Samantha Stosur (AUS x5) bt Christina McHale (USA) 2-6, 6-4, 6-0
Li Na (CHN x8) bt Silvia Soler-Espinosa (ESP) 6-3, 6-1
Angelique Kerber (GER x12) bt Venus Williams (USA) 6-4, 6-1
Mikhail Youzhny (RUS) bt Javier Marti (ESP) 6-3, 6-2
Viktor Troicki (SRB) bt Donald Young (USA) 6-1, 4-6, 6-1
Ryan Harrison (USA) bt Sergiy Stakhovsky (UKR) 7-6 (7/3), 7-6 (7/5)
Nicolas Almagro (ESP x11) bt Santiago Giraldo (COL) 6-7 (5/7), 6-3, 6-3
Alejandro Falla (COL) bt Juan Ignacio Chela (ARG) 6-3, 2-6, 6-2
Igor Andreev (RUS) bt Juan Carlos Ferrero (ESP) 6-4, 7-6 (7/4)
Daniel Gimeno-Traver (ESP) bt Victor Hanescu (ROM) 7-6 (7/3), 4-6, 6-3
Guillermo Garcia-Lopez (ESP) bt Marcos Baghdatis (CYP) 6-4, 3-6, 6-4