Errani matched her career high by moving up one spot to fifth in the rankings while Wozniacki, a former No. 1-ranked player, improved two places to eighth.
Neither went very deep in last week's Western and Southern Open in Cincinnati -- Errani was beaten by her co-No. 1 doubles partner Roberta Vinci in the third round and Wozniacki fell to Victoria Azarenka in the fourth -- but both benefited from the 2012 tournament finalists being unable to reach the title match.
Li Na defeated Angelique Kerber in the 2012 Western final. This year they happened to meet in the third round, with Li again winning. Li advanced to the semifinals but lost enough rankings points to slip behind Errani. Kerber's exit two rounds earlier had her fall two spots in the rankings while Wozniacki went up two, although they are only 70 points apart.
The Western final was a blockbuster with No. 1-ranked Serena Williams taking on Azarenka, the No. 2 seed. Azarenka, with a 2-6, 6-2, 7-6 (8-6) decision, beat Williams for the second time this year -- Williams has lost only four matches in 2013 -- for her 17th career title.
Along with Williams, Azarenka and Li, the fourth Western semifinalist was a resurgent Jelena Jankovic, who moves from 15th to 11th in the rankings.
The moves are important because this is the final rankings update before seedings are set and the draw made for the U.S. Open, which begins next Monday. The seeds are expected to match the rankings.
Four Top 10 players are in the field for this week's New Haven Open. Errani is the No. 1 seed. Kerber, Petra Kvitova and Wozniacki are also entered. Kvitova is the defending champion.
The WTA's Top 10 with player's name, home country and rankings points:
1. Serena Williams, United States, 12,260
2. Victoria Azarenka, Belarus, 9,505
3. Maria Sharapova, Russia, 8,766
4. Agnieszka Radwanska, Poland, 6,335
5. Sara Errani, Italy, 5,125
6. Li Na, China, 4,825
7. Marion Bartoli, France, 4,365
8. Caroline Wozniacki, Denmark, 3,490
9. Petra Kvitova, Czech Republic, 3,440
10. Angelique Kerber, Germany, 3,420