Matthias Ginter scored the opener for Germany after a fine cross from Antonio Ruediger, while Leon Goretzka capitalized on a mistake by keeper Georgiy Bushchan to head the ball into the net.
Luis Enrique will make changes to his side on Saturday with goalkeeper David de Gea likely to replace Kepa Arrizabalaga, who will have been happy to keep a clean sheet in Lisbon after his recent troubles at Chelsea.
"I was under doubt before the match. But it's true that my level of confidence and tennis have been improving every single day during the whole tournament," said Nadal. "Of course I played at an amazing level of tennis, for two sets and a half I played great. I can't say another thing. It's impossible to have this score against him without playing great."
Game six will be played on Sunday. Enditem
Lucenec started off strongly and built a vital 12-point lead at half-time. However, the host team gradually closed the deficit in the second half.
"We played well at the start, and executed as planned at both ends, which gave us an upper hand in the first half. But back from the locker room, we didn't put enough pressure on them in defense and do well in transition," Beijing coach Zhang Yunsong noted.
"I don't know what is going on, I'm so happy," said Swiatek in a smile.
"I had already won a medal in Rio, so I am not going to be under pressure in Tokyo."
In the 76th minute, Lyu Yueyun received a pass and rifled into the net, securing the 4-0 victory for Wuhan.
Sheffield United's striker Oliver McBurnie could have made it 2-0 for the home team in the 79th minute but his promising header bounced off the crossbar of Dusan Kuciak's goal.
"I'm not just a female coach, I also want to be the inheritor of Chinese martial arts," said Liu, who speaks quickly and talks about her dreams with great enthusiasm.