Updated

By Iain Rogers

MADRID (Reuters) - Seventh seed Jelena Jankovic won a tense Serbian battle in the Madrid Open second round on Wednesday when she came from a set down to beat Ana Ivanovic 4-6 6-4 6-1.

In a match littered with errors on the clay of Manolo Santana center court, both players struggled to hold serve with Jankovic, wearing a bright green dress, breaking her orange-clad compatriot 11 times and losing her own serve on eight occasions.

Jankovic, the world number four and runner-up in Rome last week when she beat Serena and Venus Williams, will play Spaniard Anabel Medina-Garrigues for a place in the quarter-finals.

French Open champion in 2008, Ivanovic has won just one Tier II tournament since that breakthrough grand slam triumph and has slipped well down the rankings but a run to the Rome semi-finals lifted her to 42nd.

World number one and top seed Serena Williams plays 16th-seeded Russian Nadia Petrova for a place in the quarter-finals later on Wednesday.

If Venus Williams, the fourth seed, beats Francesca Schiavone on Wednesday she will rise to number two in the rankings, the first time since May 2003 the sisters have been ranked first and second.

(Editing by Ed Osmond)