The America’s Cup golden boys squared off Wednesday under overcast skies and blustery winds on the opening day of match races at the America’s Cup World Series stop the Marina Green.

For Great Britain’s four-time Olympic gold medalist Ben Ainslie, it was an afternoon of brilliant comebacks as his J.P. Morgan team debuted on the circuit.

Meanwhile for Australian Nathan Outteridge, his London success did not carry over to the waters of San Francisco Bay.

Outteridge’s Team Korea multi-hull gained early leads in both his races against Ainslie only to see victories slip from his fingers in the winds that maxed out at 17 knots.

“We certainly have a lot to learn,” Ainslie said. “We had a few issues, but the guys did some amazing work to get us around the course. We had to overtake (in both races) and I think we had a penalty call go against them that helped us in the second race, but the guys did a fantastic job.”

Outteridge felt particularly frustrated.

“We started well in the first one and then just made one error which gave them the chance they needed,” Outteridge said. “Then in the second race, we seemed to be getting penalties for no apparent reason… (and) we basically had to let him go past… We’re a bit confused about what happened to be honest.”

But the two race sweep was not without a bit of controversy as Outteridge asked Regatta Director Iain Murray to consider overturning the result and having one of the race re-sailed because of a penalty.

But after consulting the races panel of judges, Murray allowed the results on the water to stand.

In the other two match races, Prada’s two Luna Rossa multi-hulls came up victorious and also advanced to Thursday’s quarterfinals.

Max Sirena’s Luna Rossa Swordfish and Chris Draper’s Luna Rossa Piranha won their matches 2-0 over China Team and Artemis Racing Red, respectively.

 "We had a tricky one against Santiago Lange and the Artemis team,” Draper said. “We knew they’d be pretty strong. But the guys made some good reads on the wind shifts to get us in front.”