Eintracht Frankfurt winger Ansgar Knauff opened the scoring in the first minute as they beat West Ham United 2-1 in the first leg of their Europa League semifinal on Thursday, with both teams seeking their first European final in over 40 years.
The last time the two teams met in the semi-finals of a European competition, West Ham won the two-legged tie to reach the 1976 Cup Winners' Cup final.
The visitors, however, stunned David Moyes' men 49 seconds into the first half when Rafael Borre set up Knauff with a cross from the corner of the box and the 20-year-old headed home, silencing the sold-out 60,000 crowd at the London Stadium.
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After sending home heavyweights Barcelona in the quarterfinals, Eintracht players did not want to waste the opportunity presented to them in the last four.
"I don't know if I am doing anything special. But as against Barcelona, we put them under pressure right from the off," Knauff told the reporters.
West Ham had a number of chances to level the score, with including in the 14th minute when Jarrod Bowen received a beautiful pass inside the box but his effort bounced off the right post.
"Today wasn't one of our best performances," Antonio said.
"It was not how we wanted to start the game. We got control of the game and created some chances which we didn't take. It's all to play for. It's not over. We're in it to win it."
Knauff could have given Eintracht the lead again before halftime but his attempt from inside the box was well wide of the right post.
The Japan international, who netted his fifth Europa League goal this season, had a chance to score again in the 79th minute but his shot from close range crashed against the post.
"The early goal gave us a boost of course. But their goal did not put us down, we recovered well from that," Knauff said.
Frankfurt goalkeeper Kevin Trapp added: "I am not surprised by our performance. We can do this if we are fully focused, we have proven this often.
"Tonight it was another highlight for us. We wanted to make the first step towards the final."
West Ham, who advanced to semi-final after overpowering Olympique Lyonnais, continued to seek an equaliser but had no luck, as Bowen's stunning bicycle kick from near the penalty spot rattled the bar in stoppage time.