Having been stretched to three sets in his opening three matches this week, Nadal finally put in a complete performance with a 6-2, 6-2 win over Grigor Dimitrov in the semifinals on Saturday.
“Today was a good confirmation that I really played better. … A lot of positive things,” Nadal said. “[Djokovic] is playing great and it's going to be a really tough match.”
Nadal holds a 22-18 career edge vs. Djokovic but the Serb won their last meeting for the Sony Open title in March in Key Biscayne, Florida.
Nadal already has a record seven titles in Rome, while Djokovic is seeking his third championship at the Foro Italico. They have met in three finals here, with Nadal winning two of them.
Using vocal crowd support to her advantage, Errani fought back from a 4-1 deficit in the second set for a 6-3, 7-5 win over two-time Rome champion Jelena Jankovic.
Williams is aiming for her third Rome title, having won this clay-court tuneup for Roland Garros in 2002 and last year. The American is 6-0 in her career against Errani and lost just one game in their last meeting, in the semifinals of last year's French Open.
“She's just taken her game to a whole new level and she has so much confidence beating two really good top-10 players and two really great clay-court players,” Williams said, also referring to Errani's win over second-seeded Li Na in the quarterfinals. “So I have a lot of work to do tomorrow. It's not going to be easy. And she has nothing to lose and she has the crowd behind her. So it's going to be a really tough match for me.”
Nadal went the distance against Gilles Simon, Mikhail Youzhny and Andy Murray in his opening rounds this week but had relatively little trouble against Dimitrov, who was playing in his first Masters series semifinal.
Djokovic's win was a struggle, with Raonic serving near 140 mph and firing 16 aces.
“I can't recall the last time when I was feeling so helpless in the return games,” Djokovic said. “It was brutal.”
Afterward, Djokovic appealed for help for his flood-hit native Serbia, and wrote a message of support on a camera lens, adding `I love you' in Cyrillic.
“This is a total catastrophe of biblical proportions,” he said. “Half the country is in danger of not having electricity.”
Errani drew emotion from the crowd.
“There were a few moments when I thought I might not pull it off but the fans were huge,” said Errani, who is attempting to become the first Italian to win the tournament since Raffaella Reggi took the 1985 title in Taranto.
The last Italian man to win was Adriano Panatta back in 1976.
It's already Errani's best result since reaching the 2012 French Open final.
Jankovic, the 2007 and 2008 Rome champion, repeatedly asked the chair umpire to come down and check marks but none of them were overturned, resulting only in the crowd stepping up its encouragement for Errani.
“Just do it, Sara. Just do it, Sara,” the fans cheered late in the second set.
The highly partisan crowd frequently applauded Errani while points were still being played and cheered even when Jankovic double-faulted.
“(The crowd) was all on her side but it's normal, she's the local player,” Jankovic said. “I tried to stay focused on my game, and play my tennis but she was the better player today.”