Olympics-Swimming-Italy's Ceccon quickest in 100m freestyle heats

Maybe I don’t even need a middle lane,” he said, a reference to 18-year-old Tunisian Ahmed Hafnaoui, who won gold in the 400m freestyle from the outside lane. China's Zhang Yufei, who narrowly missed out on gold in the 100m butterfly won by Canadian Maggie MacNeil on Monday, posted the fastest time in the women's 200m fly.

Italy's Thomas Ceccon was fastest in the heats of the 100m freestyle on Tuesday ahead of favourite Caeleb Dressel of the United States and Rio gold medallist Kyle Chalmers of Australia.

Ceccon posted a personal best time of 47.71, two hundredth of a second ahead of Dressel, while Chalmers was a further four hundredth behind. The world record time in the event is 46.91. With the semi-finals to come, it was clear that the majority of the contenders were content to just make it through to the next round of qualifying.

"Everyone is just playing games and I'm one of them," said Chalmers. "I ticked the box to get through the rounds and now I need to conserve as much energy as possible…. Maybe I don't even need a middle lane," he said, a reference to 18-year-old Tunisian Ahmed Hafnaoui, who won gold in the 400m freestyle from the outside lane.

China's Zhang Yufei, who narrowly missed out on gold in the 100m butterfly won by Canadian Maggie MacNeil on Monday, posted the fastest time in the women's 200m fly. Zhang lead with 2:07.50, a full 0.81 faster than American Hali Flickinger with team mate Yu Liyan third fastest.

Hungary's Katinka Hosszu skipped the event, to avoid a busy 200m butterfly 200 medley schedule in Wednesday's final.