Cambridge defeat Oxford after swimming man forces Boat Race restart Cambridge (right) and Oxford in training, this year's Boat Race has been halted after a man was spotted in the water near the crews. Photograph: Richard Heathcote/Getty Images Cambridge won the 158th staging of Boat Race on Saturday - but a potentially thrilling contest was interrupted by an intruder in the River Thames. Oxford held a slight advantage heading into the final bend when umpire John Garrett called a halt to the race after the swimmer narrowly avoided being hit by the blades from the Dark Blue boat. The race was eventually restarted at the half-way point after a 31-minute delay. Oxford pulled half a length clear when a clash left No6 man Dr Hanno Wienhausen with a broken oar. At that point the race was over and Cambridge pulled clear to win. Umpire Garrett warned Oxford cox Zoe de Toledo to move across just before the clash. De Toledo argued the wash in the River Thames was too strong for her to move fast enough but her appeal was rejected. Umpire Garrett said his assistant, Sir Matt Pinsent, spotted the swimmer first. Garrett told BBC Sport: "There's something in the water. We thought it was debris then we realised it was a swimmer. It was clear he was waiting for the boats so I had to stop the race. The rules state clearly that crews have to abide by their accidents, unless one of the crews has caused that accident. In the immediate run-up to the clash I was warning Oxford. Cambridge were in the right position so I was content to let the race continue and the result stand. Oxford bow man Alex Wood, 27, was carried off the Dark Blue boat and given medical treatment after the finish line.