Azarenka raced out to a 3-0, double-break lead on British No.1 Watson en route to a comfortable first set win. And though she relinquished an early break advantage in the second set, she broke right back and went on to a comfortable 6-2, 6-4 win that saw her convert on five of six break points.
"I started really well and played pretty consistently throughout the whole match," Azarenka said. "She stepped up her game in the second set. I felt like I started to be less dominant for a couple of games, but then I brought it back and stepped up when I needed to. I was aggressive and moved well. It was a better quality match than my first match, and I was more consistent and took a lot more chances."
Azarenka is now 4-0 in her head-to-head with Watson, though this was by far their closest match, as she surrendered just five games combined in their three previous encounters.
"I always want to improve," Radwanska said. "I think it's a progression from match to match. I think I can get even more consistent, even more aggressive, place my shots better, take my chances and go forward more."
Next up for Azarenka is third-seeded Agnieszka Radwanska, who down a break at 2-1 in the third set against Sabine Lisicki won five of the next six games for a 6-1, 3-6, 6-3 victory in which she converted on five of six break points.
In the process, Radwanska got a measure of revenge for her dramatic three set loss to Lisicki in last year's Wimbledon semifinals and secured her first quarterfinal berth since Rome in May.