[USER (data scientist)]: I have a dataframe of tennis matches played on grass courts. I want to find notable opponents that the top 10 players struggle against. The term 'notable opponents' refers to opponents who have played at least three matches with the specific player. Can you help me write a code to do that? Please generate and display a list of opponents who have won at least three matches against the top 10 ranked players on grass surfaces in the ATP tennis dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import numpy as np
import pickle

atp_tennis = pd.read_csv("atp_tennis.csv")

# YOUR SOLUTION BEGIN:
<code1>
[COMPLETE YOUR CODE] 
</code1>
# YOUR SOLUTION END

print(notable_opponents_list)

# save data
pickle.dump(notable_opponents_list,open("./pred_result/notable_opponents_list.pkl","wb"))

---END CODE TEMPLATE---

[YOU (AI assistant)]: Sure, I can help you with that. First, Here's a code snippet to find the notable opponents who have won against the top 10 players:
'''
import pandas as pd
import numpy as np
import pickle

atp_tennis = pd.read_csv("atp_tennis.csv")

# YOUR SOLUTION BEGIN:
