Baysa made a strong start to 2010 by becoming the first foreign athlete to win the women's race at the Xiamen International Marathon. She led the race uncontested and finished in 2:28:53. Despite cold conditions, she also won the Paris Half Marathon in March, recording a time of 1:11:05. She set her eyes on defending her Paris Marathon title in April and her front running tactics succeeded in record time: finishing in first place in 2:22:04, she beat Marleen Renders' course record which had stood since 2002 and knocked over two minutes off her previous best. She ran at the 2010 Chicago Marathon in October and started well by setting a fast pace from the beginning, establishing a significant lead by the halfway point. The worsening heat proved too much for the athlete, however, and in the final 10K Liliya Shobukhova gained a three-minute lead over her, leaving the Ethiopian in the runner-up position with a time of 2:23:40. She entered the Delhi Half Marathon in November but managed only fifth place over the half distance.
She ran a time of 2:23:13 hours at the 2012 Dubai Marathon, which was only worth eighth place in a fast women's race. She won the Tarsus Half Marathon in a course record of 69:39 minutes in March before going on to place ninth at the 2012 London Marathon. While running at the 2012 Chicago Marathon, she drew on her experience of 2010 and did not falter in the second half of the race, racing away in the final section to beat Rita Jeptoo to the Chicago women's title. She ended the year with a dominant performance at the Montferland Run, winning unchallenged after breaking away from the pack in the first 5 km of the race.