The below is a beautiful display of Muay Thai. Both Buakaw and Petnamek throw beautifully and utilize their technique in rather different strategies to impose their will on the fight.
This bout, in addition to being a fun to watch display of Muay Thai, also serves to highlight a difference in scoring between Muay Thai and kickboxing or Western boxing. Namely, that the judges weigh the last two rounds heavily over the first three. This makes sense on paper, but for those of us who are used to seeing each round weighed equally, it seems strange on viewing.
Of the fighters, Buakaw is undoubtedly more famous, due to his successes in K-1. At this point, he was still fighting in the 135 - 140 lb (61.5 - 63.5 kg) range. It would be two years before his debut in that organization. He now fights at 154 lb (70 kg), which is also his walk-around weight.
Like Buakaw, Petnamek Sor Siriwat was a well-regarded fighter on the Muay Thai circuits during this time. He too would move up in weight. I believe the most recent footage of him on Youtube showed him participating in Muay Thai vs San Da in 2005.
Buakaw fights out of the blue corner in this bout, Petnamek, southpaw, fights out of the red corner.