I'm watching the first Underworld film right now, and what happens during the flashback is that Viktor walks in and takes the key from around Sonja's neck, and turns to Lucian, who begins to transform due to a full moon. He fully transforms, breaks his chains, and as he stands up Viktor draws his sword. Viktor was standing there with his sword out as if he were ready, and Lucian still smacked him down to the ground. I thought that Lucian got a hit while Viktor was pulling out his sword, but Viktor had his full attention on Lucian, meaning that Lucian has to be somewhere around Viktor's strength/skill level.