Unseeded Sania, a silver medallist at the Commonwealth Games in Delhi, scored an upset 6-2 6-3 win over Thailand's Tanasugarn to reach the women's singles semifinals.
The 166th ranked Indian, a silver medallist at 2006 edition in Doha, relied on her power-packed strokes to beat the Thai, who once figured in top-20 and now stands at number 58 in the world.
Sania escaped unscathed in a tough opening game, in which she saved six breakpoints, and gradually took control over the contest, which lasted one hour and 27 minutes.
She will next face third seed and world number 69 Akgul Amanmuradova of Uzbekistan.
Somdev, who has already won a bronze in the men's team event, assured himself of another bronze in the men's doubles by reaching the semifinals along with compatriot Sanam Singh.
They beat the Chinese pair of Yan Bai and Zhang Ze 6-2 6-4 in the men's doubles quarter-finals at the Aoti Tennis Centre.
Somdev and Karan Rastogi also inched towards the medal round in the men's singles event by progressing to the quarter-finals.
Second seed Somdev won at the expense of just two games as he beat Uzbekistan's 16th seed Vaja Uzakov 6-1 6-1 in the third round at the Aoti Tennis Centre.
The ranking difference between the two players was all the more palpable as 105th-ranked Somdev took just 39 minutes to dispatch the 960th ranked Uzbek.
However, Somdev did not rate his opponent low saying, "my opponent is a talented player. I had to focus on my game. I served well. I am happy with my performance."
He will next take on sixth seed Chinese Zhang Ze, who is ranked way behind the Indian at 307.
"I have a good chance. It does not matter who I face next," Somdev said when asked about his next clash.
Rastogi, coming back to international tennis after an injury lay-off, did not have much trouble in thrashing Taipei's 10th seed Ti Chen 6-0 6-4.
After blanking his rival in the opening set, the 332-ranked Indian dropped his serve in first game of the second set but broke 525-ranked Chen in the eighth game to draw parity and broke him for again in the 12th game to clinch the issue.
"I started off well. Chen is a good player but I knew what to expect and stuck to my game. In the second set, I played a loose first game and my service was broken, but I am happy I could pull it off," he said after the win.
Rastogi's first real test comes now as he faces top seed and world number 40 Denis Istomin of Uzbekistan next.
"He is the top seed. I just want to enjoy the game when I get on court. Who knows what is going to happen," he said.
If Somdev and Rastogi manage to win one more match, they will be assured of at least a bronze medal in the singles event.