Here you go:

https://morepypy.blogspot.com/2011/08/pypy-is-faster-than-c-...

https://morepypy.blogspot.com/2011/02/pypy-faster-than-c-on-...

For more examples, just search "pypy faster than c".

Also, here is an article from the Python wiki about why speed doesn't really matter a lot of the time:

https://wiki.python.org/moin/PythonSpeed

And, my own two cents:

Speed is relative. Does every piece of code need to be as performant as possible? No. I would argue that, in most cases, speed of development is far more important than speed of execution. This is, of course, not true for things like drivers or statistical analysis.

Writing a web application? Speed isn't that important as the whole process is i/o bound anyways.

Writing a machine learning algorithm? Depends.

Web scraping? I/O bound, speed not really important.

Image processing? Speed matters at least a little bit.

Writing networking glue for distributed systems? Speed probably doesn't matter.

It's all relative. If it needs to be fast, it needs to be fast. Most things don't really need to be fast. For the things that don't need to be fast, why build them with C/C++/Rust/Go when you could spend half the time building them in Python/Ruby/js/etc?