Novak Djokovic reaches final

MASON, Ohio -- No medal involved this time. Little drama, either. Novak Djokovic simply ground his way to another tournament title match.

And Roger Federer will be waiting for him.

Djokovic reached the final of the Western & Southern Open for the second straight year Saturday, beating Juan Martin del Potro 6-3, 6-2 in a reprise of their Olympics match. Del Potro defeated Djokovic for the bronze medal on Wimbledon's lush grass two weeks ago.

The sequel on a hard court? Not even close.

The final will match the world's top two players, the first time that's happened in Cincinnati.

"It's a nice bonus, really," Federer said. "When I was a kid I wasn't thinking of winning five Cincinnatis, but then again here I am in this great situation being able to do it, the first man ever. So I'm obviously excited. Very often when I do now reach a finals there is something on the line. Here we go -- there is something there."

Top-ranked Federer beat Swiss countryman Stanislas Wawrinka 7-6 (4), 6-3 in the other semifinal. It'll be the seventh time that Federer and Djokovic have played for a tournament title, the last time in 2011 at Dubai. Federer beat Djokovic for the Cincinnati title in 2009.

On the women's side, Venus Williams played through a bad back that forced her to get treatment and reduced her second serve to 63 mph in the third set. China's Li Na reached the final of the Western & Southern Open with a 7-5, 3-6, 6-1 victory on Saturday night.

Li is trying for her first title this season. She lost in finals at Sydney, Rome and Montreal, where Petra Kvitova beat her for the Rogers Cup title a week ago.

Germany's Angelique Kerber rallied past Kvitova 6-1, 2-6, 6-4 in the other semifinal on Saturday, giving her a chance to play for her third title this season. Kerber ended Serena Williams' 19-match winning streak Friday.

Federer leads their career series 15-12, but it's taken a few interesting turns lately. Djokovic beat him in the semifinals at the U.S. Open last year, then again in the semis at Rome and the French Open. Federer got the upper hand again in the semifinals at Wimbledon.

"I hope I'm fresher than him tomorrow," Federer said. "We'll see how it goes."

Djokovic also reached the Cincinnati finals last year but had to quit in the second set because of a sore shoulder, giving the title to Andy Murray.

This week is going much better for him.

He won the Rogers Cup in Toronto last Sunday night, leaving him a little tired, but he managed to get some rest at the suburban Cincinnati tournament. He was on court for only a half-hour Thursday night, when Nikolay Davydenko had to quit their match because of a sore shoulder.

The Serb had played only three sets the past two days, leaving plenty of energy for his second semifinal in eight days.

He used it in the long rallies.

Djokovic and del Potro exchanged a lot of shots from the baseline in the first set, with both players wasting chances to take control early. Djokovic got to the semifinal by holding serve in all 22 games during the tournament, facing only four break points. He faced that many in the third game of the match.

The Serb saved one of those break points with a 30-shot rally that ended with del Potro dumping a backhand into the net, then dropping his head.

"We played long rallies," Djokovic said. "It could have easily gone the other way. I managed to hang in there and play my best when I needed it."

One of del Potro's biggest concerns is his left wrist, which has nagged him for some time. The right-hander will have it checked before the U.S. Open by the same doctor who operated on his right wrist in 2010, when he missed most of the season while recovering.

During the first set, del Potro looked at his left wrist and shook it after a tough backhand shot, an indication those long rallies were stinging.

"Yeah, it's bothering me all the time, and I don't want to risk too much," del Potro said. "I have experience in wrist problems, and I would like to take time to fix this little problem."

Djokovic broke him to go up 4-2 and served it out. He broke him again for a 2-1 lead in the second set, when del Potro seemed to lose his edge.

At one point, he thought about quitting because of the painful wrist.

"I'm playing well, even this match," he said. "And the crowd here is very nice. It (center court) was full today, and I didn't retire because Djokovic is my friend and I have a lot respect of him and I want to finish the match."

The men's draw in Cincinnati took a hit this year when Rafael Nadal had to withdraw because of a sore knee. Nadal hasn't played since Wimbledon and has already pulled out of the U.S. Open because of the injury.

Federer's semifinal win set up a memorable finish.

He skipped the Rogers Cup, resting after the Olympics. He hasn't lost a set all week, making quick work of his opponents -- until Saturday.

By every measure, Wawrinka was overmatched. He came in 1-10 in his career against Federer, including 0-7 on hard courts. He'd lost his last eight matches against the Swiss star, dropping 19 of 20 sets.

More bad history: Wawrinka came into the match 0-9 against players currently No. 1, losing all 19 sets against Federer, Nadal and Djokovic when they were at the top of the rankings.

He nearly had a breakthrough Saturday, fighting off five set points to take the opener to a tiebreaker. Federer pulled it out, taking advantage of a couple of backhand shots into the net by Wawrinka. The first set lasted 58 minutes.

That was Wawrinka's best chance.

Meanwhile, Venus Williams showed all week long she's learned how to cope with an immune system disease that causes tiredness and sore joints. She made it through three grueling, three-set matches to get to the semis, and was ready for another one.

The bad back was too much. By the end, she was just trying to get her serve over the net. She considered quitting, but decided to keep playing.

"I pretty much couldn't serve," she said. "But I wanted to try, especially since this is my first semifinal of the year. I wanted to try to see if I could get to the final. It didn't work out for me."

Serena Williams watched from a seat in the stands next to the players' tunnel while her older sister wore down. At one point in the final set, she yelled: "Break her!" Venus smiled, knowing she was in no shape to do it.

Her semifinal loss aside, it's been a kick-up-your-heels week for Williams, who faded last year because of injuries and the immune system disorder. She's on an upswing heading into the U.S. Open, which she had to miss last year because of the disorder.

She won an Olympic gold medal in doubles with her sister at Wimbledon, a moment she called the best of her career. On Cincinnati's hard courts, she reached her first semifinal of the season by winning one long match after another.

Li had the most challenging time of the women this week in Cincinnati. She had the last match on Thursday night, and it got postponed by rain. She ended up playing two matches a few hours apart on Friday, winning both of them to reach the semifinals.

Li beat Johanna Larsson 6-2, 6-2 in the opener on Friday morning. She took the court less than seven hours later and beat top-seeded Agnieszka Radwanska, who had a sore shoulder.

On Saturday, Williams was the one struggling. She said the back started to bother her during warm-ups and got worse as the match went along.

"Right now, I don't know why my back hurts," she said. "I just know it hurts. After this, I'm going to get an evaluation and see what exactly is happening."

Li noticed the speed on Williams' serve diminishing.

"I saw her serve and was like, `What's going on?" Li said.

After the third game of the second set, Williams called for the trainer. She placed a white towel on the court and lay face-down for several minutes while the trainer worked on her lower back for several minutes, with Williams wincing.

"I thought the match to be over," Li said.

Not even close. Williams went back out on the court and broke Li's serve to even the set at 2-all.

Williams had trouble getting anything on her serve -- she moved stiffly -- and ambled to her chair during breaks, leaning down to stretch her back. With the crowd cheering every point, she kept playing and kept winning, breaking Li again to go up 4-2 and serving out the set.

Before one serve early in the third set, she started to raise her arm to toss the ball and had to stop because of her back. She then served at 66 mph -- and held serve. One of her second serves clocked 63 mph a few games later.

Williams pushed herself to the end. She ran down a ball for a put-away slam in the last game, which Li won when Williams hit a return long -- her 47th unforced error during the 2-hour, 8-minute match.

Williams smiled as he walked to the net to shake hands.

"I like to live life with no regrets," she said. "I don't want look back and feel like I gave up or say I could have done this or that. That's not me. I wanted to go the very end and at least know that maybe I missed some shots or maybe I wasn't feeling my best, but I gave it my all."

Kvitova led the final set of her match slip away. Her double fault helped Kerber break to go ahead 3-2. The Czech had 15 unforced errors in the first six games of the set.

She avoided a match point in the ninth game, but Kerber served it out.

Information from The Associated Press was used in this report.