Team New Zealand have dealt a huge blow to America's Cup holders Oracle with two commanding wins on the opening day of racing in San Francisco today.

Already down two points before the action started, the Americans are now on the back foot.



And it's not just on the points board.



Team New Zealand showed a decided edge in boats speed and crew work to claim victories by 36-seconds and 52 seconds in winds of 16-19 knots.



It was a tough day's work though - finally there was some close racing.



The first race was particularly tight with the opening two legs seeing just four seconds between the two boats. The lead changed three times Kiwis on the upwind third leg with Aotearoa's dominance finally coming to the fore there as they stretched clear.



The second race was far more comfortable.



Once again Dean Barker did a fantastic job in the prestart to get the better of Jimmy Spithill and claim the windward side. Team New Zealand got over the line first, threw some dirty air on the Americans, and never relinquished that lead.



Barker and his tactician showed classic match-racing tactics as they covered anything Oracle tried to throw at them, covering them all the way.



All the predictions that these boats would be close, look to be correct.



But all the suggestions that Team New Zealand's added time on board their boat would help them also proved correct. They looked far slicker.



Oracle even lost a crew member overboard in the buildup to race one and then had some problems with a tear in their wing sail that had to be patched with tape to start the second race.



"What we saw was one hell of a yacht race and it's only going to get harder," Barker warned after winning race one.



A delighted Davies was a bit more exuberant after the second race: "That was a fantastic day."



He praised Barker's work in the prestarts, particular in the second race when he got the better of Spithill with a tight manoeuvre.



Spithill appealed for a penalty - as he did twice in the first race - but was again denied.



"That was a touch-and-go moment for the race. That was spot-on," Davies said.



"That was pretty much the race to be honest."



Spithill agreed although he was unhappy with the penalty call and even more unhappy with where they sit now.



"Obviously it's not the result we wanted," Spithill said.



"I think the boats are pretty even.



"I was surprised we didn't get a penalty. From there we weren't away to accelerate as quick as them and that was pretty much it."



Spithill refused to attribute anything to their damaged sail.



Barker believed there were some encouraging early signs.



He admitted they felt "good upwind" while downwind it seems to "come down to a little bit of positioning".



The numbers certainly favoured Team New Zealand.



They showed an edge in speed in both direction and in the first race, despite making more turns, the Kiwis were able to hold their lead.



In the second race, as the wind built, they even showed signs of foiling upwind.



Spithill, always positive though his body language wasn't good, maintained Oracle could come back.



"It's early days," he said.



Despite a number of top sporting events on in San Francisco this weekend, including both baseball teams playing and the 49ers launching their NFL season, big crowds descended on the waterfront to soak up the atmosphere and get close to the action, as the catamarans allow with shoreline viewing.



Organisers were hoping for around 25,000 through the afternoon on the main pier where the finish line is and up at the top of the course, in the shadow of the Golden Gate Bridge, they were expecting a further 10,000.



They looked to be about right. There was a real buzz around, though it was the large Kiwi contingent that had the smiles.



The racing finally brought an end to a very long build-up that included a tedious, one-sided Louis Vuitton Cup series, and a dramatic jury ruling that hammered Oracle so hard for cheating by tampering with their smaller AC45 catamarans during the world series over the past two years.



There are two more races tomorrow at the same times.