Ulti attacked Yamato again. Yamato blocked her attacks:
Luffy asked her to help Momonosuke, she continued to chat with Luffy while fending off Ulti:
After that, she left Ulti to meet Momonosuke:
Yamato never actually attacked Ulti the second time.
She was casually chatting with Luffy and having an existential crisis about Momonosuke being her son while she was fending off Ulti. Ulti was so much of a non-threat that Yamato could do this.
Luffy distracted Yamato by requesting that she should protect Momonosuke (she turned around to address him). This lead to Yamato debating whether Momo was actually her son (distracting her further). Ulti couldn't even land a hit on Yamato when she was so distracted. Compare how:
- Kamazou was able to land a hit on Zoro when he was distracted by Gyukimaru.
- Hawkins was able to overcome Zoro's guard and land some nails on him.
The gap between Ulti and Yamato is thus much larger than the gap between Kamazou and Zoro or between Hawkins and Zoro.
Claiming that Yamato is Ulti level would be like saying that it's an anti feat for Mihawk that he blocked Crocodile's strike.
Or that Vista is Mihawk level because he traded blows with him.