“The better team did not win today. I strongly believe that. I think you saw American heart. You saw us give everything we had today.”

WATCH: golden moments on Day 6 at the Rio Olympics

Star striker Alex Morgan and substitute Christen Press missed penalties before Lisa Dahlkvist converted the winning spot-kick despite Solo’s best efforts to put her off by changing gloves to delay Dahlkvist’s effort.

“It is OK to be coward if you win,” Sundhage shot back.

“What she did was an act of panic,” said Swedish keeper Hedvig Lindahl of Solo’s time-wasting tactics before the final penalty.

USA coach Jill Ellis tried to diffuse the row.

“They executed her game plan very well. It’s a matter of knowing how to use all the resources you have,” said the Englishwoman.

“And finally the most important thing is the result, not how to play.”

Sweden will now face either hosts Brazil, who thrashed them 5-1 in the group stages, or Australia in Tuesday’s semi-final in Rio.

“I don’t think they’re going to make it far in the tournament. I think it was very cowardly,” added Solo.

“But they won. They’re moving on, and we’re going home.”

Defeat is the Americans’ first in 15 games at the Olympics and only their third ever in Games history having won four golds and a silver since women’s football was introduced to the Olympic programme.

Morgan looked to have saved America’s blushes when she swooped 13 minutes from the end of normal time to cancel out Stina Blackstenius’s opener just after the hour mark.

But the world’s number one ranked side failed to break down Sundhage’s well-organised Swedes in extra-time, who also had a perfectly good goal from Lotta Schelin wrongly ruled out for offside in the final minutes.

“They didn’t try and press. They didn’t want to open the game and they tried to counter with long balls,” continued Solo.

“We had that style of play when Pia was our coach.”

WATCH: Relive the action involving Hong Kong athletes on Day 7 at the Rio Olympics

Sundhage insisted she had full faith the Swedes could pull off a massive upset despite scoring just twice in three matches as they sneaked into the last eight as one of the two best third-placed sides from the group stages.

“Since (the 1991 women’s World Cup) the United States had never been out of the medals in any competition. But when I looked at my players before starting the extra time and penalties and I was so confident in my players,” she added.

Solo’s Games has been dogged by controversy as she received chants of “Zika” from fans across Brazil.

Last month the 35-year-old posted a picture of herself with a mosquito net over her head and a huge bottle of insect repellent in hand with the message: “Not sharing this!!! Get your own! #Zikaproof #Road to Rio” on her Twitter account.

Germany also booked their place in the last four on Friday with a hard-fought 1-0 win over 10-man China in Salvador.

Melanie Behringer netted the winner 14 minutes from time after Chinese substitute Wang Shanshan was sent-off for two quick-fire yellow cards.

Wang Shuang had the chance to send the game into extra-time, but hit the post with a penalty six minutes from time.