New Delhi, Dec 09 (ANI): BJP President Rajnath Singh credited the party's prime ministerial candidate, Narendra Modi, for its spectacular victory in the assembly polls of four states. The BJP is the clear winner in three big states of Madhya Pradesh, Chhattisgarh and Rajasthan that went to the polls, though it emerged as the single largest party in Delhi too. Singh said the party benefited from the popularity of Modi. The ruling Congress party was defeated in key state polls, including the capital, underlining the struggle it will face to cling to power in a national election due by May next year. Congress, led by Sonia Gandhi, is facing widespread anger at corruption and high inflation after two successive terms at the head of a national coalition.