By Martyn Herman

LONDON (Reuters) - Former world number Ana Ivanovic blamed a wrist injury for a surprise first-round defeat by lowly-ranked Russian qualifier Ekaterina Alexandrova at Wimbledon on Monday.

The Serb became the highest women's seed to perish on day one, losing 6-2 7-5 to the world number 223 playing her first ever grand slam match after coming through qualifying.

"Yeah, it was very tough," Ivanovic told reporters.

"I mean, for two weeks I've struggled with my right wrist. It was very hard to accelerate on my forehand. I tried to do everything possible to be fit and recover and tape it and so on.

"But, yeah, it was a little bit sore. I feel like it caused me a lot of miss-hits."

Ivanovic, seeded 23, reached the quarter-finals of the Wimbledon warm-up event in Mallorca this month but it was there that she started to struggle with her wrist.

"It really got inflamed," Ivanovic, one of nine grand slam champions in the women's singles draw, said.

"I had a couple of days off and it started to calm down a little bit. Every time I would start hitting, it would flare up. I felt like I could probably manage it.

"But it's tough on grass when the ball really skids through. She was hitting very heavy. It was disappointing."

Ivanovic was not the only seed to lose on Monday.

In the men's singles, South African Kevin Anderson, seeded 20, lost to Denis Istomin of Uzbekistan 4-6 6-7(13) 6-4 7-6(2) 6-3, while Frenchman Pierre-Hugues Herbert beat 21st-seeded German Philipp Kohlschreiber 7-5 6-3 3-6 6-3.

(Reporting by Martyn Herman; Editing by Ken Ferris)