Well, 'One-Punch Man' could fit. The protagonist sometimes takes on enemies alone with his unique powers. Another option could be 'Fist of the North Star', where the hero is known for his solitary fights.
You might consider checking out 'Naruto'. There are instances where Naruto has to fight alone to prove his strength and protect his friends. Also, 'Sword Art Online' has moments where the main character finds himself in solo battles.
Chapter 103 is the strongest chapter-level answer because it starts from Jiang Yan looked at Zhao Lang with suspicion, eyeing the dark substance in... and follows through on Jiang Yan felt deep guilt welling up inside him..
A practical answer is Chapter 91, because it turns the idea into a concrete scene. The chapter opens with When Jiang Li saw that he had been assigned a harrow, Qi Tianyu felt his..., adds pressure through Jiang Yan, you have to work hard this afternoon;
The best chapter pointer here is Chapter 77, "Why are you sabotaging me again?". It opens with Wen Jiaojiao's reminder calmed Shu Yan down. and closes on But who knew that the next second, the lottery box would be handed over to....
If you want the clearest chapter reference, go to Chapter 72. Early on, Jiang Yan was still griping when suddenly a fair hand reached out beside...; later, the chapter leans on I'll take these, thank you." In an instant, five pairs of eyes stared over....
Look to Chapter 53 for the clearest answer. It begins with Night had fallen over Chixia Village, eerily void of any human sounds., keeps building through Jiang Li followed the village chief's wife down a narrow path leading to..., and lands on Wait, did this kid accidentally fall into the water?].
Look to Chapter 70 for the clearest answer. It begins with So, under the curious gazes of everyone, Jiang Yan strutted up with his..., keeps building through He didn't even take off his sunglasses before he started reading into the..., and lands on He Yun was also surprised as he looked towards.
A practical answer is Chapter 66, because it turns the idea into a concrete scene. The chapter opens with I can't take it anymore, why did the young master even find a pair of..., adds pressure through If adults can't sort out their own breakfast, what good are they?, and ends on Unable to find a.
If you want the clearest chapter reference, go to Chapter 74. Early on, Having seen Jiang Li's ID before, he knew that this person named Shiguang...; later, the chapter leans on And he only knew the answer to that one question..
If you want the clearest chapter reference, go to Chapter 81. Early on, Qi Tianyu, who chose curry beef rice, received a piece of curry and a...; later, the chapter leans on Shu Yan was relatively lucky, she got a bundle of noodles and a bag of....
A practical answer is Chapter 59, because it turns the idea into a concrete scene. The chapter opens with After walking for about two or three hundred meters, the old man stopped..., adds pressure through Your brother might just be kind enough to take you in., and ends on My phone, my cigarettes.