In 2010, she won the gold medal in the 400 metres hurdles at the Commonwealth Games, and was runner-up at the African Championships and also took a silver medal for Africa at the Continental Cup. She still holds the Nigerian record in the 400 m hurdles, after improving on her personal best to 54.40 seconds during the 2012 London Olympics semi-finals.
At the University of South Alabama, Odumosu represented the college's South Alabama Jaguars team, she was the 400 m Sun Belt Conference champion in 2004 but missed most of the 2004–05 season due to injury. In 2006, she became the indoor 400 m Sun Belt champion and took a sprint and hurdles double at the outdoor meeting. She reached the NCAA Championships final that year, but was disqualified due to knocking over a hurdle.[1] She improved her personal record to 55.37 seconds to win at the Drake Relays in 2007 – a world-leading mark at that point of the season.[1]
She reached the top of the continental rankings with a gold medal at the 2008 African Championships, taking the hurdles win in 55.92 seconds.[5] She made her first Olympic appearance in August 2008, running the 400 metres sprint in Beijing. She set a personal best 51.39 seconds to progress through the heats, but she was eliminated in the semi-finals.[6] She ran in the 4×400 metres relay and reached the final where the Nigerians finished in seventh placed.[7]
At the 2009 World Championships she reached the 400 m hurdles semi-finals and was sixth overall with the women's relay team. She also set a meeting record at the Ponce Grand Prix, where she won in 55.02 seconds. Odumosu set a Nigerian record at the Herculis meeting in July 2010, running 54.68 seconds for fifth in the hurdles.[8] She returned to defend her hurdles title at the 2010 African Championships, but she had to content herself with the silver medal behind Hayat Lambarki. She still reached the top of the podium at the competition, however, as she helped the 4×400 m relay team to a championship record of 3:29.26.[9] Along with Lambarki, Odumosu was selected to represent the African team in the 400 m hurdles at the 2010 IAAF Continental Cup. She improved her national record to 54.59 seconds at the competition and secured the silver medal behind Jamaican Nickiesha Wilson, running for the Americas.[10]