It’s that time of the year again, to take a step back in time to remember this year’s Dextro Energy Triathlon ITU World Championship Series through the eyes of some of the world’s best sports photographers. They were on hand to capture every twist, turn, and colourful moment in the each and every world series race, but now it’s your turn to decide the official ITU Photo of the Year by voting on your favourite image below. Each weekly winner then earns the right to appear in the ITU Photo of the Year final. In addition to the contest, readers will hear from each event photographer about their favourite shot from the event, which will be published alongside the winning pictures from each week.

In week five of this competition, we revisit one of the biggest events of the year; London. It was the first and last time that athletes could race the course before the London 2012 Olympic Games and there was plenty to take away from how each race played out. The London course features some iconic spots and it’s no surprise that Buckingham Palace and Wellington Arch on Constitution Hill feature in the eight finalist images from photographer’s Delly Carr, and for the first time this year, Janos Schmidt.

In the women’s race, Great Britain’s Helen Jenkins couldn’t have picked a more perfect time and place for her first series title - at home, in the Olympic preview. But it was a big day for all three medallists, as the USA’s Gwen Jorgensen and Germany’s Anja Dittmer also secured their spots for the London 2012 Games with their places on the podium. In doing so, Dittmer also became the first triathlete - male or female - to qualify for four consecutive Olympic Games. Read the race recap and watch video highlights here.

In the men’s race, it wasn’t necessarily a surprise that Alistair Brownlee won, but it was interesting how he did it. On the flat, fast and technical bike course, it looked like a bike breakaway would be hard,  but Brownlee managed to do it with the help of New Zealand’s James Elvery and then ran solo for 10km to claim his third win of the year. Russia’s Alexander Brukhankov finished 25 seconds back with silver, followed by Jonathan Brownlee with bronze. Read the race recap and watch video highlights here.

Remember to scroll to the bottom of the images and vote for your favourite, to determine which image from London makes it into the final of the 2011 ITU Photo of The Year.