Results from autoclave experiments show that vacuum resid from Maya crude can be hydrocracked to a high yield of light liquid product. However, in order to achieve this high conversion (> approximately 90%) without also generating a high yield of coke, the reaction rate must be low during the initial rapid conversion reactions. This allows the hydrogenation rate of the thermally generated fragments to outpace their rate of condensation to coke. After the initial rapid conversion reactions are complete (> approximately 50% conversion), the temperature can be raised and the reaction rate increased without generating significant amounts of coke. Analysis of the feed and products supports a conversion mechanism involving the cracking of largely aliphatic fragments away from a largely aromatic core, with this core becoming increasingly refractory as conversion proceeds.