* Federer sees off Anderson in straight sets
* Li, Pennetta into women's semis (Adds Federer quotes)
March 13 (Reuters) - Roger Federer charged into the semi-finals of the BNP Paribas Open at Indian Wells on Thursday with a straight sets win over South African Kevin Anderson.
The Swiss master succeeded where others had failed by blunting the serve of the towering 6ft 8in (2.13m) Anderson to win 7-5 6-1.
Federer faced only one break point in the entire match and reeled off seven games on the trot to clinch the opening set and race to a 5-0 lead in the second.
His reward for winning was a semi-final clash on Saturday with Ukrainian giantkiller Alexandr Dolgopolov, who continued his fairytale run in the Californian desert by defeating big-serving Canadian Milos 6-3 6-4.
"It was big to win the set and then to go on to break early in the second," Federer said. "Then (getting a) double break was like a bonus. From then on I was home basically.
"It was a really good match for me, basically."
In the women's draw, China's Li Na won her rematch with Slovakia's Dominika Cibulkova to join Italian veteran Flavia Pennetta in the semis.
In her first meeting with Cibulkova since the Australian Open final in January, Li once again proved too strong for her younger opponent, winning 6-3 4-6 6-3 in a little over two and a half hours.
Pennetta booked her place in the last four by beating American Sloane Stephens 6-4 5-7 6-4 in a seesawing match played in gusting winds.
In a tournament that has been packed with surprises and high-profile casualties, the 32-year-old Li has been a model of consistency, ferociously battling through each round.
The Chinese top seed, in the absence of world number one Serena Williams, has struggled with her serve all week and committed eight double faults against Cibulkova, four in the opening set and four more in the third when the pressure was on.
The Slovak also made eight doubles while the pair combined for more than 100 unforced errors in a match that was longer and much tighter than their last meeting in Melbourne.
Li got the decisive break late in the third set and then served out for victory to stay on course for her first title at one of the biggest events outside the grand slams.
"Here is different than Australia. Of course score should be different," said Li.
"I think today she played more aggressive. I was feeling if I try to go back like a little bit she was trying to step in to hit the ball.
"Also I was feeling in the second set I think I dropped down a little bit and gave her more chance. She can get a lot of winners."
Pennetta looked to be heading for the exit when she blew her first chance to win the match then fell behind in the deciding third set.
The 32-year-old was two points from victory when serving for the match in the second set when the wind suddenly started to blow a gale and her game started to unravel.
Stephens, 20, broke her serve and won six games in a row to jump out to a 3-0 lead in the third when Pennetta staged her own comeback, winning six of the last seven games to wrap up an extraordinary victory.
"We didn't play our best tennis," Pennetta said. "Maybe in the beginning we played much better, and in the second one, but the third was a disaster for both of us.
"I'm happy to get through this match, but I don't have good feelings right now - it's just crazy outside, the wind is just coming out of nowhere."
Dolgopolov has been a revelation at Indian Wells since he was thrust into the spotlight when he scored an upset win over world number one Rafa Nadal in the third round.
Players who register shock wins often fail to maintain their form on but the 28th seed has gone from strength to strength, beating three seeds in succession.
Raonic, one of the biggest servers in tennis, beat Wimbledon champion Andy Murray on Wednesday but found Dolgopolov too hot to hold.
"I just wish I could have served better. But other than that, he did the right things at the right times right away from the start of the match," said Raonic.
"He was a factor of why I didn't serve as well as I would have liked as well."
Not only did Dolgopolov succeed in breaking the Canadian's serve three times, including twice in the second set to overcome a 3-0 deficit, but showed he also has a serve to be reckoned with as he fired six aces, two more than his opponent.
"I was really happy with that. And I was able to get more returns than usually you can against him," said Dolgopolov.
"He serves really big and I knew I had to do that, and I'm quite pleased how I anticipated on his serve and have seen the toss of the ball and was really, really concentrated to get those serves back." (Reporting by Julian Linden in New York, Editing by Peter Rutherford)