KUMAGAYA, Japan (Reuters) - Argentina coach Mario Ledesma said his team finally delivered the sort of all-court game they had been working towards for months in their 47-19 win over the United States on Wednesday, but not even the seven-try romp could lift his gloomy tournament outlook.

The Pumas had the crowd on their feet with some wonderful running and handling, even from behind their own tryline, as some of the youngsters drafted in grabbed their opportunity.

Yet the game was a virtual dead rubber for Argentina who, for the first time since 2003, will be watching the quarter-finals from home after their earlier pool defeats by France and England.

"Today was very good in lots of areas but ultimately how I feel about this World Cup is that I'm not satisfied," Ledesma told a news conference.

"We came here fighting to make the quarters and have been working very hard but we were never able to find the perfect game we were looking for. We really wanted to make it through and everyone is disappointed that we couldn't, but the motivation was still there today but it was from inside, from the heart."

Despite his frustration Ledesma was, however, delighted with how some of his fringe players grabbed their opportunities, with all seven tries being scored by backs.

"Argentinian rugby has a bright future," he said.

"The youngsters were incredible today. The way we played today was actually similar to how it was in 2015 (when they reached the semi-finals) and we have been working hard to mix things up.

"We've scored several tries from driving mauls in this World Cup, the scrum was pretty consistent here, so I think it's a case of trying to use the pack to get go-forward and a consistent set-piece and then we have exciting backs who can deliver as we saw today.

"We were able to score some really good tries in the match and the players played with real joy."

Captain Pablo Matera was also frustrated.

"We played three matches but couldn't really show what we've practiced for the full 80 minutes in any of the games," he said.

"But everyone gave their all today. We were playing for the shirt but also for the players who are leaving us. It was Juan Manuel Leguizamon's last game and he's the man today and we're very happy to give him a victory in his last game."

The flanker's 87th cap came 14 years after his first and Leguizamon was hoisted shoulder-high by his team mates on an emotional lap of honour.