Italy's Flavia Pennetta stunned former world number one Maria Sharapova 6-2 4-6 6-3 in the semi-finals of the LA Championships on Saturday.
Top seed Maria Sharapova won her seventh straight match on US soil by defeating holder Elena Dementieva 6-3 6-4 in the quarter-finals of the Los Angeles Classic on Friday.
Top seed Maria Sharapova ended Anna Chakvetadze's 12-match winning streak and powered into the San Diego Classic final with a 6-3 6-2 victory over her Russian compatriot on Saturday.
Number two seed Sharapova will face 13th seed Tatiana Golovin of France on Thursday, who beat Luxembourg's Anne Kremer.
Serena Williams has withdrawn from next week's Stanford Classic due to a thumb injury, organisers said on Thursday.
She will play number 14 seed Daniela Hantuchova of Slovakia, who wore down number 12 Li Na of China 7-5 4-6 6-1.
In the semi-finals, the 13th seeded Murray will meet 12th seed Novak Djokovic of Serbia, who overpowered 14th seed David Ferrer of Spain 6-3 6-4.
Second seed Nadal outfought Argentine Juan Ignacio Chela 7-5 7-5 and third seed Roddick overcame Croatian Ivan Ljubicic 7-6 7-6.
Second seed Svetlana Kuznetsova beat Czech teenager Nicole Vaidisova 4-6 6-3 6-4 to move into the Pacific Life Open semi-finals on Thursday.
Daniela Hantuchova maintained her good form at Pacific Life Open with a gritty 6-2 5-7 7-6 victory over Israeli 11th seed Shahar Peer in the quarter-finals on Wednesday.
The 19-year-old Scot will meet the winner of the match between fifth seed Fernando Gonzalez of Chile and ninth seeded German Tommy Haas in the quarter-finals.
They reached the fourth round of the Pacific Life Open on Monday.
World number one Roger Federer suffered a stunning 7-5, 6-2 upset defeat by Argentine Guillermo Canas in the Pacific Life Open second round on Sunday.