UPDATED 8.01am: In scenes reminiscent of the Evers-Swindell sisters eight years ago, Mahe Drysdale has won rowing gold in a photo finish.

Radio Sport's Sports Editor Rikki Swannell said the wait felt like an eternity - whether it was Drysdale, or Croatian Damir Martin who’d won single sculls gold.

With 400 metres to go it looked near certain for the kiwi but Martin surged again and they crossed the line simultaneously, a photo finish.

But it wasn’t quite simultaneous.

While they’ll be credited with the same time it came down to thousands of seconds, and Drysdale had nosed his black boat in front.

Drysdale said neither he nor Martin had any idea who who it until it came up on the screen.

"Fantastic, I looked at the replay and I probably got him on the surge, because I think he was just in front before the line, and oh that's horrible. Horrible way to finish it you know, 400 to go I thought I had it comfortably, and full credit to Damir to come back from there."

It's back-to-back gold medals for the amiable kiwi with the iron will, making him New Zealand's oldest Olympic champion.

Drysdale said the young members of the team have spurred him along.

"That keeps you on your toes and pushes you along, just keeps me going."

"It's really just a number, age, you don't really think about it too much, though I have started to feel it as the recovery takes longer."