On the 2010 Diamond League circuit she won at the Bislett Games and was ranked second overall in the 400 m behind Allyson Felix. Montsho ran her fastest time of the year at the 2010 Continental Cup where, representing Africa, she beat Debbie Dunn to win the gold medal in 49.89 seconds. She extended her season further to compete at the 2010 Commonwealth Games. There she became Botswana's first ever gold medallist at the Games by winning the 400 m with a Games record time of 50.10 seconds. She then helped the Botswana team to the 4×400 m relay final, but they finished in seventh place.