Fastest way to sort an array in descending order

Why is the following code

Array.Sort(values);
Array.Reverse(values);

much faster at sorting an array in descending order compared to

Array.Sort(values, (a,b)=>(-a.CompareTo(b)));

Code was run in Release mode outside of the debugger.

What is the most efficient way to produce a descending sort for arrays, preferably in a one liner?