Nadal in devastating form thrashed the 20-year-old 14th seed 6-2 6-4 6-0 in one hour and 46 minutes.
The 32 year old Nadal picked up 28 winners, breaking Tsitsipas’ serve six times and only facing one break point himself.
He is now waiting to play either top seed Novak Djokovic or France’s Lucas Pouille who will meet on Friday.
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“It was a great match, it has been a great tournament and I have played very well every day,” Nadal said.
“Hopefully I can play better than that.”
Nadal who lost in last year’s semi-finals of the US Open is looking strong after a number of injury problems.
He had to pull out of the Brisbane International earlier this month with a thigh strain and the move has paid dividends for the 17 time Grand Slam champion.
“To start the season like this when a few weeks ago I was in Brisbane having to take a tough decision not to play there, it is difficult to imagine where I am today,” Nadal said.
“But I never stopped practising. That week of practice made me feel good.”
Nadal has looked sharp in his six matches on his way to the final and has still not dropped a set.
He has played three players – Alex de Minaur, Frances Tiafoe and now Tsitsipas – who are aged under 21 and competed in the Next Gen finals.
“They don’t need me to send them a message – they are good,” he said.
“It is always a big challenge to play against them. They are a young and new generation that are already here fighting for the most important things.”
The second seeded Nadal is one more victory away from making history by winning all four Grand Slams a feat which no one has achieved in the Open era.
Meanwhile Djokovic will also make history if he defeat Pouille in his semi-final clash which will give him a record seventh men’s singles title.
Tsitsipas who has a very strong serve and forehand was playing in his first Grand Slam semi-final and became the highest ranked player to face Nadal in the tournament.
The spaniard Nadal won all of his first serves he landed in the first set, backing that up with a strong 63% on his second serve, allowing him to put pressure on Tsitsipas.
Tsitsipas had to play some stellar tennis in this second set after dropping the first to Nadal 2-6 but was yet to create a break point opportunity.
The third game saw Nadal breaking his serve for a 2-1 lead which Tsitsipas had to produce a two double faults and the Spaniard pounced for a 5-2 advantage before serving out the opener in 31 minutes.
According to Nadal, Tsitsipas has everything to become a great champion
“There are not many reasons to be down when you have started the season like this, even if is normal just straight after the match not to be happy,” he said.