Tsitsipas did well to serve out at love in the first game but Nadal took over as he broke back in each of his next two chances before sealing the opening set in 34 minutes when the world number 27 sent a routine forehand into the net.
The Greek teenager, who turns 20 on Sunday's final day, defeated his third straight top 10 opponent at the tournament after knocking out Dominic Thiem in the second round and 13-time major victor Novak Djokovic in the third.
"I've lost a handful of tough matches this year but I feel like I'm starting to play better now, a little more consistent", the 30-year-old Californian said. "I am looking forward to play the final". Also this season, she fell in the quarter-finals at the Australian Open in January against Elise Mertens, and was stunned by Mihaela Buzarnescu in the third round at Roland Garros. "I can not believe it", the superstar tennis player said.
"Hopefully I can end the year on a strong note".
Williams skipped the Rogers Cup in Montreal last week after suffering the heaviest defeat of her career at the hands of Johanna Konta in the opening round of the Silicon Valley Classic. For me just having this trophy with me means a lot.
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Several days later Erdogan accuses Washington of showing an "evangelist, Zionist mentality". We have not made concessions on justice so far, and we will never make any".
"Playing in a Masters 1000 final is the best thing that can happen on your birthday", Tsitsipas said. "It's been the key factor", Tsitsipas said on Saturday.
But Federer believes the time off and his need to preserve his body - he played just 57 matches previous year compared to 97 at his peak - has given him a simpler path, mentally as well as physically.
Tsitsipas had a mini-break in the tie-break but Nadal fought back and took his first match point with a forehand victor.
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Kelly came on board he told me she was a loser & nothing but problems. "He doesn't know how to control himself". Oh, oh, cheese and crackers, I- I don't love that you are leaving but, but I do love cheese and crackers'".
"You've got to keep it all in perspective, it's easier now for me to take time away".
"I try to play every match with the highest possible passion, it's a special feeling that I have on court".
The world's number one ranked player went on to praise Tsitsipas in his post-match interview, although it was the sportsmanship of the 32-year-old which stole the show. I'm just fortunate to be back here on these courts playing tennis.
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However, any concerns about a lack of fresh faces were quickly alleviated in an end-to-end opening at a sun-kissed St James' Park. Distance the ball was over the line, according to goal-line technology, as Tottenham led through Jan Vertonghen .