Switzerland's Roger Federer serves the ball to Croatia's Marin Cilic during their men's singles second round tennis match on Day 5 of The Roland Garros 2021 French Open tennis tournament in Paris on June 3, 2021. (ANNE-CHRISTINE POUJOULAT / AFP)

LONDON - Tennis great Roger Federer said Switzerland's shock Euro 2020 victory over world champions France on Monday showed that the tournament underdogs can move mountains.

Speaking at Wimbledon, where he edged through his opening match on Tuesday, the Basel native said Switzerland should now take it to the next level against Spain on Friday.

"It was a great football day yesterday overall just in terms of quality of matches," Federer said of Switzerland's penalty shootout win after the last-16 game ended 3-3.

I was really proud of the way they fought. It just shows in sports, in football in particular, when the team pulls together, really believes, that you can move mountains really.

Roger Federer, Swiss professional tennis player

"I just thought they fought super well. With the situation of being up 1-0, missing the penalty, then everything changing within half an hour. It would have been so easy just to let go.

"I was really proud of the way they fought. It just shows in sports, in football in particular, when the team pulls together, really believes, that you can move mountains really."

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Bizarrely the Swiss 20-time Grand Slam champion was up against Frenchman Adrian Mannarino on Tuesday and looked in danger of going out as he trailed by two sets to one.

But he won the fourth set after Mannarino injured himself and was spared a decider after his opponent withdrew.

Federer lost the equivalent of a soccer penalty shootout in the 2019 Wimbledon final as Novak Djokovic edged a fifth set tiebreak -- the first ever played in a Wimbledon final.

So the 39-year-old had some sympathy for France striker Kylian Mbappe whose spot kick miss sent the Swiss through.

"Penalty shootouts are so brutal. Obviously on the edge of your seat. That was me, too. I feel bad for the French team and the players because I like to watch them a lot," he said.

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"Now I hope the best for Switzerland. I hope we can replicate another match like this, not celebrate too hard, take it to the next level. That would be historic for us at a big event like this to go into the semis."