"I didn't think that was ever going to happen, to be honest."
After his first-round victory last week, the 25th-ranked Shapovalov credited his improvement on grass, in part, to the Swiss, explaining: "I've been trying to watch a lot of Roger - how he plays on the grass, how he comes in, chips, how he bothers players on the surface".
Nadal hit 37 winners to only 12 unforced errors and erased the only break he allowed by breaking back immediately in the third set.
The 22nd-seeded Mannarino became the first man to earn a break point against Federer at the tournament, but was unable to take any of his four opportunities.
The road to recovery following elbow surgery has been rocky for Djokovic, but there were signs of a revival during the clay-court season, which included a run to the French Open quarter-finals, while this rebirth was all-but confirmed with his display at Queen's last month.
Elsewhere, Roger Federer advanced to a record-extending 16th Wimbledon quarterfinal with a 6-0, 7-5, 6-4 victory over Adrian Mannarino of France. Isner, 33, will be playing in his first quarterfinal at the majors since the 2011 U.S. Open when he faces former Wimbledon finalist Milos Raonic. Nadal then plays Jiri Vesely of the Czech Republic.
"He started to play better from the baseline and I made a couple of mistakes with the game I lost with my serve".
"I'm very pleased to be back in the second week".
"It's definitely helped a certain style of player, maybe the big servers", said 20-time major victor Federer.More news: Donald Trump urged to avoid controversial Supreme Court pick
It's clearly not the first time Federer has honed his skills with a cricket bat.
After seven years of struggles, Rafael Nadal is finally looking like a contender again at Wimbledon.
Federer, who plays Kevin Anderson in the quarter-final of the Wimbledon is on course for a ninth title at the iconic All England Club was invited by Tendulkar to exchange notes about cricket after he wins his ninth crown.
Djokovic, seeded 12th, won easily over Russia's Karen Khachanov, 6-4, 6-2, 6-2.
Elsewhere in fourth round action, Dominika Cibulkova launched a scathing attack on Wimbledon's officials after a line call controversy marred her 6-4, 6-1 win against Taiwan's Hsieh Su-Wei.
The Argentine is one of the most popular players among tennis fans, not least because he has had to overcome serious wrist injuries which left him contemplating ending his career.
Anderson added that Federer, who won his first Wimbledon title in 2003, is the flawless role model for the sport - and for those players in the chasing pack. I'm really happy for you.
"I actually did get a bit emotional that I was in the last 16 of a Grand Slam that I have been dreaming of winning one day", Tsitsipas said.