Washington, May 25 - An Indian-American boy Rahul Nagvekar has won the National Geographic Bee Championship with an educated guess about the Bavarian city that was a legislative seat of the Holy Roman Empire from 1663 to 1806.

The 14-year-old from Sugarland, Texas, correctly answered the geography stumper by naming the city Regensburg on the Danube River to vanquish another Indian-American geography bee veteran, Vansh Jain of Minocqua of Wisconsin, who was making his third appearance in the finals here Thursday.

Indian Americans swept all the top three positions. As champion, Nagvekar won a $25,000 scholarship and an all expense-paid trip to the Galapagos Islands.

Second place finisher Jain won $15,000 in scholarship, and the third place winner, Varun Mahadevan from Fremont, California, won a $10,000 scholarship.

Approximately four million students from across the US participated in the competition this year.

Newcomer Nagvekar later admitted to ABC News that it was just an educated guess in what the host Alex Trebek described as either the "year of the rookie or the year of the veteran" finals.

Nagvekar, who said he fell in love with geography when his parents gave him a globe at the age of three, said he didn't expect to win the competition on his first try, but stuck to a plan throughout the contest.

"Truthfully, no. I was not necessarily expecting to win. But at the same time I knew that if I was calm and I focused on everything and I listened to all of the questions then I would be able to get a good number right and I knew I could do well if I executed the plan properly," Nagvekar told ABC News.

Nagvekar celebrated his 14th birthday Tuesday during the start of the preliminary competition, making his win Thursday an extra special birthday gift.

"It was a wonderful present. I don't think I can ask for more," he said.

President Barack Obama joined in on the competition, taping a video message congratulating the participants and asking them to answer what city hosted the Nuclear Security Summit he attended this March. Nine out of 10 contestants in the finals answered correctly with Seoul.

(Arun Kumar can be contacted at arun.kumar@ians.in)