After a perfect first set for the Dane (only two unforced errors I think), Pavlyuchenkova made it more competitive in the second, trying to turn the match her way (basically keeping more her powerful strokes in the court). But Wozniacki was rock solid to hold her serve for a 4-3 lead despite being down 0-30, answering with two aces and another excellent first serve followed with a strong, deep crosscourt forehand. That's how you keep an opponent from turning the match around.
Caroline never let it go and even held for a 5-4 lead after a crosscourt forehand winner (against Pavlyuchenkova, whose forehand is one of the best of the tour, that's saying something).
Basically, Wozniacki kept more balance than Pavlyuchenkova during competitive and powerful rallies, which explains her far best percentage of unforced errors, and her best chances to win when both are in the zone.
The rally at 5-4 and 30-15 on Nastia's serve illustrates this very well. Wozniacki got to 30-30 and forced the Russian to a mistake during very strong rallies. Same to get a match point at 30-40. But Pavlyuchenkova pulled out her best game to stay with the Dane at 5-5. Also did her best trying to break Wozniacki in the following game (that got to 30-30), unsuccessfully as Wozniacki kept serving strong and stayed rock solid.
In the end it's Wozniacki who broke the Russian for the victory, keeping Pav's powerful shots in the court.