A 12-year-old Indian-origin boy has clinched a prestigious spelling championship here, beating 30 others in the final showdown. Ashvin Sivakumar, a class VI-tudent at the Anglo-Chinese School, spelled his way to the top spot at the ‘RHB-The Straits Times National Spelling Championship’ on Saturday. He won the title after spelling the word “pulchritudinous” in the 10th round.Kua Le Yi, 10, from Catholic High School came second.