Luke beats Mace in lightsaber combat more often than not.
A few points why you can't use the Mace-Sidious fight as an example for Mace's lightsaber victory. Luke knows shatterpoint just as Mace does. Sidious has way more anger, darkness to be turned against himself than Luke. These were the two main reasons why Mace beat Sidious.
Mace is an amazing duelest, but he is not in NJO Luke's league. Mace defeated, which itself is arguable, Sidious due to Vaapad's superconducting loop, however he will not have this advantage against Luke. Luke, however, managed to defeat DE Sidious through his own skill/power. A far more impressive feat.
Intresting fact, Luke may have created a new version of Vaapad in TUF. While Luceno has never stated it was Vaapad, he said he made is sound like Luke was using Vaapad on purpose.