TORONTO: The United States finally nudged Canada from top spot on the Pan American Games medal table on a sweltering Saturday that saw scorching conditions and sizzling performances.

As temperatures climbed into mid-30s Celsius (95 Fahrenheit) and officials issued a heat alert the red-hot Americans were piling up podiums across the city.

Laura Zeng, 15, won the rhythmic gymnastics all-around, 2012 Olympic champion Kim Rhode struck gold in the women's skeet, Khatuna Lorig hitting the bulls eye in women's individual archery and Paige Railey sailed away with gold in the women's laser radial.

But it was American swimmers who made the biggest splash, snatching three of six gold medals on offer on the last day of competition in the pool.

Natalie Coughlin, a 12-time Olympic medalist and the Games' biggest name, finally got her first Pan Am gold helping the United States to victory in the 4x100m medley relay.

After settling for silver in the 100m free and 4x100m freestyle relay and a bronze in the 50m free, Coughlin saved her best for last, reaching the top of the podium in the final women's event.

"I had a really successful meet, I did exactly what I was set-up to do on my path next year to the Olympic Games," said Coughlin. "As a team, I think we did a really fantastic job. We kept building every single day and we got closer as a team and had a lot of fun swimming as well."

Allison Schmitt, winner of five medals at the 2012 London Olympics, was also part of the relay effort, collecting her third gold medal to go along with a silver.

Caitlin Leverenz and Sierra Schmidt had the other U.S. golds, touching first in the 200m individual medley and 800m freestyle.

The United States was also on fire on the wrestling mat, getting gold from 2012 Olympic champion Jordan Burroughs in the 74kg weight class, Kyle Snyder in the 97kg division and Zack Rey in the 125kg.

The United States have dominated the Pan Ams, topping the medal standings at every Games since 1955 and winning over 2,000 more medals than the next closest nation Cuba.

For a week, Canada had refused to concede to their southern neighbors until Saturday when the United States took over at the top with 50 gold and 135 total medals.

With eight more days of competition, Canada holds onto second with 48 gold and 122 medals overall.

The rivalry looks to pick up steam in the second week on several fronts.

The United States set up a showdown with Canada for baseball gold after Andy Parrino cracked a two-out, walk-off single in the bottom of the ninth to give the Americans a dramatic 6-5 win over Cuba.

Canada, meanwhile, cruised into the title game easing past Puerto Rico 7-1.

It was also a productive day for Brazil, the 2016 Olympic hosts picking up gold in both men's and women's windsurfing gold, group all-around rhythmic gymnastics, men's 4x100m medley relay, Henrique Rodrigues in the men's 200m individual medley and Yane Marques, bronze medalist at the London Olympics, taking top spot in the modern pentathalon.

The athletics competition opened with Peru's Gladys Tejeda winning the women's marathon, a challenging course through Toronto's High Park, beating out 2011 Pan Am gold medalist Adriana Da Silva in hot, humid conditions.