UPDATE 1-Tennis-Jankovic overcomes back pain to reach last eight

(Adds quotes)

By Gennady Fyodorov

MOSCOW, Oct 9 (Reuters) - World number one Jelena Jankovic survived a scare before reaching the Kremlin Cup quarter-finals with a 6-7 6-3 6-2 win over Vera Dushevina on Thursday.

The Serb, who replaced Serena Williams at the top of the WTA rankings on Monday, was in danger of becoming the third high-profile player to bow out of the $2.3 million tournament.

Jankovic, making her Moscow debut, lost the first set and was 0-2 down in the second before finding her range to subdue the 77th-ranked Russian.

Jankovic said she had been ready to quit the match after losing her serve early in the second set.

"I just couldn't do it anymore at that point as I felt a pain in the back," she told reporters.

"I was ready to shake hands and finish the match but I said to myself, 'Just try every point, try your best'.

"I don't know how I managed to win today," she said.