Wanjiru made a triumphant United States debut in 2 hours 5min 41sec to defeat Moroccan Abderrahim Goumi by 23 seconds and shave a second off the old race mark set in 1999 by America's Khalid Khannouchi.

The victory, which came in the fastest marathon time ever clocked on US soil, was worth $75,000 (£48,000) plus a $100,000 (£63,400)-bonus for a race record he nearly squandered by slowing near the end to wave twice at cheering spectators.

Wanjiru said: "I was very happy.

"I was happy to take $100,000 by one second."

It was the fourth triumph in five career marathons for Wanjiru, who turns 23 next month, and his third major triumph in a row after last August's gold medal in last year's Olympics in Beijing and his London victory six months ago.

Kenya's Vincent Kipruto, who set a Paris Marathon course record of 2:05.47 in just his second career marathon, was third in 2:06:08 with countryman Charles Munyeki fourth in 2:07:07.

Shobukhova took the women's crown in 2:25:55, surging ahead at the final water break to defeat German runner-up Irina Mikitenko, this year's London Marathon winner, by 36 seconds with Russian Lidya Grigoryeva third in 2:26:47.

Shobukhova said: "It is a great surprise.

"It is very exciting."