Both Cirstea and Sema were making their debuts in Pattaya and it was the Romanian who settled the quicker on the hardcourts of the Dusit Thani Hotel; Cirstea, the No.7 seed this week, broke serve early in the first set and never relinquished the momentum, wrapping the match up 62 62 in just 74 minutes.
This quickfire victory is the latest sign of a return to form for Cirstea. After seeing her ranking drop outside the Top 100 last spring, the 21-year-old has gradually been working her way up the rankings again and now stands on the verge of breaking back into the Top 50, having won 20 of her last 25 matches - including a first round upset of Sam Stosur at the Australian Open.
Next up for Cirstea will be the winner of Tuesday's match between Misaki Doi and Thai wildcard Noppawan Lertcheewakarn.
The only other main draw singles match on Monday was also a one-sided affair, as Anastasia Rodionova defeated Iryna Brémond, 64 60. Facing Rodionova in the second round will be either No.4 seed Maria Kirilenko or Casey Dellacqua.
Kirilenko is one of seven seeds in action on Tuesday. Also getting their campaign underway will be defending champion Daniela Hantuchova, Dominika Cibulkova and top seed Vera Zvonareva, who will face Nungnadda Wannasuk, Anne Keothavong and Varatchaya Wongteanchai respectively.