USA Sevens coach Al Caravelli glowed with pride at the side of the Adelaide Oval pitch and visibly grew six inches - up to about five foot 9.

Caravelli may be small of stature, but he and his team are back to punching well above their weight in Sevens and his players did him proud on Sunday in reaching a first ever World Series Cup final, a massive breakthrough.

When Chris Wyles, Takudzwa Ngwenya, Todd Clever, Justin Boyd and several other key players flew the nest to concentrate on 15s it was difficult to see the USA being truly competitive for a little while in Sevens, but Caravelli, who himself played for Argentina, has managed to turn around his young team's fortunes in double quick time.

A shot in the arm for several of the leading rugby nations, the USA's success also offers another glimpse into the future of Sevens as a truly global, Olympic sport.

Video: Adelaide Highlights including USA's maiden final



"This is a first for our men's Sevens team, but hopefully not the last," said Caravelli.

"It was great to make a first Cup final, especially after the hiccup that we had against Australia, for the guys to dig deep and rebound I'm very proud of them."

Although the USA lost heavily against the hosts in their pool, victories over England and Niue saw them through to the Cup quarters and further successes against Wales and Argentina - last year's World Cup Sevens winners and runners-up - brought the cherished first Cup appearance.

Caravelli: Every game is a final

"I think more important than reaching a first Cup final is playing against quality teams and getting up for those games. We like to say that every game we play is a final and we always train to play 10-minute halves (for the Cup finals), we just never had yet.

"The team was really up for the final, but Samoa has a quality side and we made a couple of mistakes that we didn't do in the earlier matches."

All the more impressive was that the Eagles progressed through using a pool of just 10 players. With outstanding centre Paul Emerick serving a three-game ban for a dangerous tackle and Caravelli's newest NFL recruit Tommy Saunders mostly restricted to a watch-and-learn brief, much was asked of the other 10, who responded superbly.

Captain Kevin Swiryn led from the front alongside outstanding forward Matt Hawkins. Mark Bokhoven and Leonard Peters brought muscular impact, Zach Test and Nese Malifa class outside and Zach Pangelinan a sniper's instinct off the bench.

"I think one thing that I've learned from my peers, people like Titch (New Zealand coach Gordon Tietjens) and other guys sharing things, is that you put your best seven out every time, you have to," added Caravelli.

"Those players need to know that they can go a full 20 minutes at a time, and that's what they're learning as well."

Swiryn: Too many mistakes against Samoa

"We had a pretty nice run," said the captain Swiryn. "We didn't play our best and Samoa played really well. We did make a lot of mistakes, and you can't win in Sevens making mistakes.

"But I told the boys that we can't be down right now and then be happy when we win the Shield. We just got second place at a World Series event, but you still have that feeling of disappointment because you've lost," he added.

"The boys will be up and ready (for Hong Kong). We just have to get better and build more."

Like the rest of the teams now in Hong Kong, the USA will not have long to prepare with only a few days before the grandest Sevens event of the them all on Friday.

The USA face Fiji, Portugal and Thailand in their pool but will need to either top the group or finish as one of the two best runners-up to reach the Cup quarters for a second week running.

"We played six very physical and mentally tiring games, it's tough to rebound from that. We have all hands on deck to get the guys ready for our matches," said Caravelli.

"We need to keep going forward in our development and continue to grow as a team. We'd like to consistently make the top eight, and that means we have to play a tough game, every game.

"We need to get in the mentality of making every game a final. I have a lot of faith that these guys will be up for that."