Mahe Drysdale was choking back the tears after winning the Olympic single sculls gold medal.

Physically and emotionally spent, Drysdale struggled to string a sentence together after the most anticipated rowing race in four years came to its conclusion.

The 33 year-old beat his main rival Ondrej Synek by just under a boat length in two-horse war down the Dorney Lake course.

"That was the toughest race of my life," he said.

"I had Synek coming at me and I was just looking for the finish line, hoping it was going to come before I fell over like I did in Beijing.

"It was what I wanted to do  - that was how I wanted to race it, just take the sprint out of Synek and it worked to perfection.

"Obviously I can't quite believe it. I have been working for this for 12 years ... now I've achieved it."

Drysdale first went to the Olympics in 2004, when he finished fifth in the coxless pair.

He then rowed himself into the hearts of New Zealanders when he took bronze in the single sculls in Beijing in 2008 despite being severely affected by a gastrointestinal infection.

"My career was incomplete without this. I can't quite believe it" Drysdale said.

"This morning I was miserable because I hadn't won in Beijing. That would've taken a lot of pressure off, knowing you were Olympic champion.

"I knew I needed that. I wanted that and I had to go out and perform and when you get one race to do it, that's tough"

The singles sculls was the final race on the penultimate day of rowing and the crowd of 26,000 were on their feet for the final 1000m as Drysdale and Synek went toe-to-toe and Great Britain's Alan Campbell won the race for third.

"All my family and friends were here and my friends and the crowd was amazing.

"It was an experience I will remember for the rest of my life.
"There's been plenty of doubts. There were times in 2010 when I didn't even know if I was going to get back in the boat.

"Six weeks ago I was lying on the ground in Munich hoping my shoulder was going allow me to row. Even here, a couple times things weren't quite going how I wanted them to, my quarterfinal was was a really tough race, but today I pulled it out."

- © Fairfax NZ News