Where is it beating Java by any significant amount? The regex benchmark uses Java's native regex matcher, whereas the golang implementation uses a PCRE regex matcher, so not an apples to apples comparison. The mandelbrot benchmark are minutely different on my machine (2.06s vs 2.13s). Note that the test machines that websites use are quite old (certain optimizations or available APIs the JVM has are not supported by those older processors).

Now if you look at the bottom of the list, you'll see where Java far outperforms golang, especially in the binary-trees benchmark (12.67s vs 9.14s and 25.19s vs 8.28s in favor of Java both times).