Li beat Mattek-Sands 6-4, 6-3 and earned a spot in the final against the defending champion Maria Sharapova.
World number five Li Na withstood a late comeback from Petra Kvitova to beat the fifth-seeded Czech 6-3 7-5 on Friday and set up a Stuttgart Grand Prix semifinal with American qualifier Bethanie Mattek-Sands.
Russia completed a remarkable fightback to beat Slovakia 3-2 in a dramatic Fed Cup semifinal by sweeping the last three rubbers on Sunday.
Novak Djokovic ended Rafael Nadal's eight-year reign at the Monte Carlo Masters with a clinical 6-2 7-6 victory in the final on Sunday.
Current anti-doping measures in tennis are a "disaster" and the introduction of biological passports can only improve matters, world number six Tomas Berdych said.
The French Open should consider protecting Rafael Nadal with a higher seeding to avoid a potential quarterfinal clash with Novak Djokovic, according to Roland Garros committee member Guy Forget.
Chinese tennis player Li Na, the first Asian woman to win a Grand Slam title, was named on Thursday among Time magazine's most influential people in the world, along with NBA player LeBron James and Italian soccer star Mario Balotelli.
Novak Djokovic's gamble on his injured ankle at the Monte Carlo Masters appeared to be backfiring before he dug in to battle past Russian Mikhail Youzhny 4-6 6-1 6-4 in the second round on Wednesday.
Novak Djokovic will be hoping his gamble to play in the Monte Carlo Masters does not leave his claycourt season going bust after he decided to test his injured ankle in the glamorous principality.
Pakistan were disqualified from their zonal Davis Cup tie last weekend because the referee showed bias towards their opponents New Zealand, doubles specialist Aisam Qureshi said on Wednesday.
Novak Djokovic overcame a painful ankle injury to beat Sam Querrey on Sunday and provide Serbia with an unassailable lead over the United States in their Davis Cup quarter-final in Idaho.
Novak Djokovic believes he has left his recent poor form behind and will be in top shape when he leads Serbia in this weekend's Davis Cup quarter-final tie against the United States.