MIAMI: Tunisia’s Olympic gold medallist Ahmed Hafnaoui won the 400m freestyle at the Pro Swim Series in Fort Lauderdale, Florida, on Thursday, clocking 3min 46.02sec to grab a second gold of the week.

Hafnaoui, who won the 1,500m freestyle on Wednesday, beat Egypt’s Marwan El Kamash (3:47.34) and American Kieran Smith (3:48.02).

The second night of the meeting saw 16-year-old world champion Summer McIntosh win the women’s 200m butterfly in 2:05.05 – breaking her Canadian record and world junior mark of 2:05.20 set at the World Championships in June.

“Overall I’m really happy with my race,” McIntosh said. “There’s always things to learn. My split times were different than usual, so obviously I need to fix that in training. But a PB is a PB and hopefully I can gain more extra milliseconds next time.”

Montreal native Ilya Kharun broke the Canadian record in the men’s 200m fly, clocking 1:54.49.

American Katie Grimes also completed a 1,500m-400m double, winning the 400 in 4:05.18 ahead of Hong Kong’s Siobhan Haughey and American Claire Weinstein.

Grimes was fifth at the last turn but came home in 29.17sec to win.

“I had a strategy going into it, and even though it seemed like I was pretty far behind halfway, I just told myself to stick with it and it would work out,” Grimes said.

American Abbey Weitzeil won the women’s 100m freestyle in 53.38, with distance great Katie Ledecky second in 54.01. Erika Brown was third in 54.39.

Trinidad and Tobago’s Dylan Carter won the men’s 100m free in 48.28, beating Britain’s Matthew Richards by 20-hundredths of a second. Hunter Armstrong was third in 48.95.