Follow The Athletic’s Wimbledon coverageWelcome to the Wimbledon briefing, where The Athletic will explain the stories behind the stories on each day of the tournament.On Day 10, heartache for the last American man standing and a first-time semifinalist embracing the grass.How did the last American man standing fall?Alexander Zverev, the No. 2 seed at Wimbledon and the French Open champion, is hard enough to beat on an average day at the office.Get him on a day when he lands his crushing first serve more than 80 percent of the time, and it’s going to be close to impossible — even on the grass of Wimbledon, where his results pale in comparison to those at the other Grand Slams.After a 6-4, 6-4, 6-2 thrashing of Taylor Fritz, the No. 6 seed and the last American man standing, the 29-year-old German has landed in the Wimbledon semifinals for the first time. He’d not previously been past the fourth round.Coming into the match, Fritz was Zverev’s nemesis. He held a 10-5 record and beat him last month on grass in Germany. He’d won their past seven matches.What's the longest rally in tennis history?Tifo SportsGrass is also arguably Fritz’s best surface. His serve skids across the turf, and his chip returns either float to the baseline or cut into the front of the court, handcuffing opponents in ways the 28-year-old American can’t find on hard courts and clay.None of that bothered Zverev on Wednesday afternoon on No. 1 Court. It was his third consecutive day on the court, because his fourth-round match against Jiří Lehečka (13) didn’t finish before the 11 p.m. curfew on Monday, and that didn’t bother him either.Instead, it was Fritz who seemed worn down and worn out. He has been playing through knee tendinitis for much of the season. He has said he felt great the past 10 days, but he received treatment on his right knee during the second set.“I would have liked to feel 100 percent and try to give him a match,” Fritz said in his news conference.“I felt fine, felt really good in my warm-up actually. Felt like my warm-up was great. Then, yeah, I have no answers as to why three games in it was like that.”Still, he could have had the two healthiest knees in the world, and probably still would not have won.