"(All) you can do is hit as hard as you can side to side, be accurate and make him move, otherwise you can just play it back to him.it just keeps coming back".
Zverev took his opportunities in the final set and finished the encounter with 43 winners to Federer's 21. "I played great tennis and didn't do unforced errors or anything like that".
But Tsitsipas showed admirable resilience to fight back and win the second set 7-5.
"I don't think it's right to wait because you kind of surrender when you wait", he said.
[WATCH LIVE 1] With a win in Sunday's final, Medvedev would join Zverev as only the second non-Big Four member to win multiple Masters 1000 trophies in a single season since David Nalbandian in 2007.
Pospisil failed to capitalize on five set points in the first set, including two chances in the tiebreaker.
"When I was serving for the match he changed it again, surprised me again", Medvedev said.
"He had the high-quality tennis and he played very well after his serve", the 32-year-old Serb said of world number seven Tsitsipas.
Fifth-seeded Alexander Zverev of Germany now stands between Medvedev winning his seventh career title and third of this year. The German served for the match at 5-3 in the second set, but couldn't nail down the victory until the tiebreaker.
"For example, US Open final, a great match, a great final and I was disappointed to lose so I approach the match the same way, whether it's first round or a final". Zverev won their meeting in straights sets in 2018, and Berrettini returned the favour this year.
While this was the first time in six matches that Federer lost in the quarterfinals at Shanghai, Zverev has been a tough opponent for the 38-year-old.
Djokovic - who won the Japan Open last week - has never previously failed to make the semi-finals in Shanghai. "The last few months he's probably the best player in the world". Tsitsipas takes on U.S. Open runner-up Daniil Medvedev, who overcame Italy's Fabio Fognini 6-3 7-6 (4).