Ludwig was regarded as a top lightweight in the world during 2003 and 2004, for his victories over Jens Pulver at UCC 12 and Genki Sudo at UFC 42, up until a loss to B.J.

[1] Ludwig has also received acclaim for his role in the success of Team Alpha Male operating out of Sacramento, California, which is home to numerous highly ranked mixed martial artists who have competed in organizations such as the Ultimate Fighting Championship and World Extreme Cagefighting.

He would have a successful amateur career winning twelve of his fourteen bouts and picking up three IKF International Kickboxing Federation Muay Thai national and regional titles.

[3] At the finals Ludwig was drawn against home favourite Masato, and despite his best efforts was unable to make the semi-finals, being outclassed by the local fighter over three rounds to lose by unanimous decision.

After this victory Duane would become increasingly involved in MMA at the expense of his Kickboxing career, although he would have a number of K-1 fights up until 2006, finishing with a 4-7-1 record with the organization.

Although not an official title match, Ludwig nonetheless beat Jens Pulver, who was at the time ranked as the #1 Lightweight mixed martial artist in the world by many outlets, by first round K.O.

Despite the initial domination by Sudo, Ludwig started inflicting damage while standing, avoiding a rolling kneebar and several takedown attempts.

Whilst it seemed the momentum had shifted in Ludwig's favor, Sudo came back in the third round and took him down, pounding and bloodying him with punches and elbows.

Ludwig took advantage of the indirect rest given to him and avoided the ground and dominated the standup with several hurtful shots on Sudo to win a split decision.

Following multiple online campaigns to overturn the timekeeping error,[6] on Christmas Eve 2011, UFC President Dana White informed Ludwig that he was being given the official fastest knockout time.

"[6] Two days later, Dana White, along with his production crew posted a video to YouTube showing the times of UFC fights that hold the "Fastest Knockout" tag.

Ludwig scored with strikes, including multiple grazing headkicks in the first round until Osipczak landed a combination, buckling the veteran.

[22] The bout was stopped after Ludwig was unable to continue after tearing a knee ligament while attempting to defend a takedown in the opening round.

[25] Ludwig left Team Alpha Male after UFC 173 to focus on growing his own gym, BANG Muay Thai.

Ludwig was considered the key element in helping Team Alpha Male win Gym of the Year in 2013 by the World MMA Awards.

The system is a striking style which includes Muay Thai, Dutch kickboxing, American boxing and traditional martial arts.