Phil Robertson's Team Canada have bounced back from a capsize earlier in the week to win two of three fleet races on Saturday and take the lead in the United States Sail Grand Prix Chicago on Lake Michigan.

While the first-year Canadian team surprised the nine-boat fleet, Jimmy Spithill's Team USA had a bad day in front of home fans by going 8-9-7 to tumble to last overall.

Robertson overcame choppy water and unpredictable wind shifts off Navy Pier to win the second and third races after Peter Burling sailed Team New Zealand's foiling 50-foot catamaran to victory in the first race. Canada were fourth in race one.

Canada scored 27 points to lead Sir Ben Ainslie and Britain by one point, with New Zealand four points off the lead.

Tom Slingsby and two-time defending champions Team Australia are fourth with 21 points followed by Denmark with 18 and Spain 17.

"I guess it fills us with more confidence that when it comes to race day, we can really push it," Robertson, a New Zealander who is skippering his third team in as many seasons of tech tycoon Larry Ellison's global league, said.

After two more fleet races on Sunday, the top three crews will advance to the podium race.

Team Canada had impressive starts in all three races. Teams had the choice of approaching the line from within the harbour or from beyond the harbour wall for a longer run-up.

"We put a bit of time into assessing the different start options ahead of the race and it was pretty clear that you wanted to start outside the wall and come in fast," Robertson said.

"We managed to come ripping through the gap and come out a lot faster than everyone else."

Canada finished third in the season-opening regatta in Bermuda last month.

The American crew struggled the most on Lake Michigan.

"We're really disappointed. Certainly, all the fans deserve better," Team USA's 42-year-old Australian skipper Spithill said.

"The main failing of the team was an inability to execute clean laps. It's as simple as that. There were too many mistakes and too many errors."