SINGAPORE, Oct 20 (Reuters) - When Ana Ivanovic crunched Serena Williams's opening serve back past the world number one for a venomous winner it suggested she wasn't going to be overawed by her illustrious opponent. The Serb's own serve, however, told a different story.
The duo traded crunching groundstrokes in an entertaining opening match at the WTA Finals on Monday but Ivanovic's old Achilles' heel, her ball toss, once again returned to haunt her as she crumbled to defeat on Singapore's purple hardcourt.
Some wayward throws and wispy second serves led to the world number seven being broken at the end of each set as Williams claimed a 6-4 6-4 victory to make it eight wins in nine meetings with the Serb.
"Yeah, definitely very disappointed that both sets I made few easy errors in the last service game," Ivanovic told reporters at the Singapore Indoor Stadium.
"Especially in the first set, you know, I had a break point at four-all which I didn't use and kind of got down a little bit on myself.
"Then I rushed a little bit that service game, so that was a little bit disappointing. I felt I created lots of chances...but the serve made a big difference today."
Ivanovic briefly became world number one in 2008 after winning her sole grand slam title at the French Open but she struggled to cope with the pressure and fell out of the top 20 in the rankings.
This season, though, the 26-year-old has been able to force her way back to the prestigious season-ending eight woman event for the first time since her grand slam breakthrough after rediscovering her best, aggressive form.
She beat Serena's older sister Venus to win the Auckland Open at the start of the year, the first of four titles this season making it her most successful.
She also recorded a first win over Serena when she knocked out the American in the fourth round of the Australian Open.
Nobody has won more matches on the women's tour than Ivanovic this season, but Williams showed in their Red Group opener there is work still to do to get back to the very top.
The 33-year-old American, winner of 18 grand slam singles titles, recovered from a shaky start to find her feet and power as she chased down drop shots and blasted winners from both sides.
Ivanovic, who tossed in seven double faults, said she struggled to cope as Williams turned up the heat at the crunch moments.
"Yeah, I was rushing a little bit. She was putting a lot of pressure on my serve. She served really well today I thought and created more pressure on my service game," the Serb said.
"I didn't feel my rhythm, so I was trying to make more first serves. In the second set I did that, but against Serena sometimes that's not good enough, and it wasn't good enough today." (Editing by Julian Linden)