While Natasha remained shocked and stood in place, Xu Feng didn't bother to retaliate. It wasn't out of courtesy, but there was no longer any need for him to continue.
Since the fight was set for 3 minutes, Natasha spent most of her time multicasting.
She was oblivious that his first two sneak attacks were meant as a provocation to distract her from checking the time.
After all, he pointed out the timer in the sky to remind Natasha and made her take a glance. And when a person had just checked the time. It would be weird for them to check it again when they were concentrating on something else.
Moreover, Natasha was heated in terms of emotion and only wished to decimate him in one go.
Everything was under his calculation and played out exactly like he intended for.