The unseeded Indian, ranked 85, lost 4-6 3-6 to his seventh seed opponent in the singles event of the USD 1,214,50 hard court tournament.
Statistically it has been a successful year for Somdev as he touched a career-high rank of 62 this season but lost in the first rounds of several ATP tournaments.
Reaching the final of the Johannesburg event and the pre-quarterfinals of the Indian Wells Masters remain the highlight of his season.
Somdev did create chances today against Stepanek, who also figured in top-10 at one time in his career, but the Indian could not convert much of the break points he earned.
In all, he managed to get seven chances but converted only two and dropped his serve twice in each of the two sets.
The Indian challenge is still alive in the ATP 500 event with Rohan Bopanna and his Pakistani partner Aisam-ul-haq Qureshi competing in the doubles.
The Indo-Pak pair has been given the top billing and they open their campaign against Brazilian pair of Marcelo Melo and Bruno Soares.