http://news.yahoo.com/s/ap/20091028/ap_on_sp_te_ne/ten_wta_championships]Safina retires with injury at WTA Championships (AP)[/URL]



AP - Dinara Safina retired with a lower back injury Wednesday against Jelena Jankovic at the Sony Ericsson Championships and will lose her No. 1 ranking to Serena Williams if she has to withdraw from the tournament.