She later moved up to marathon and won the Olympic bronze medal in that event at the 2012 London Games.

Petrova won the 5000 metres silver medal at the 2003 European Athletics U23 Championships, finishing behind Turkish runner Elvan Abeylegesse.

[1] Petrova began competing in road running events and took back-to-back wins at the Monument Avenue 10K from 2004 and 2005.

[4] The following year she took the steeplechase silver at the 2007 World Championships (in a personal best time of 9:09.19 minutes) and came close to a medal at the 2008 Beijing Olympics, taking fourth behind Russian teammates Gulnara Samitova-Galkina and Yekaterina Volkova and Eunice Jepkorir of Kenya who took silver.

She stayed with them until the final kilometre, when she fell back into bronze medal position and ended up finishing third in a personal best of 2:23:29.