[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. Can you help me write a code to do that? Please generate the code with the output in list type.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import numpy as np
import pickle
from decision_company import read_csv_file, count_unique_values, check_elements_in_list, reset_index, convert_to_np_array, convert_np_to_list

atp_tennis = read_csv_file('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
<code1>
[GENERATE 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:

# MY SOLUTION BEGIN:
