Strong sales of Avengers vs X-Men and its AvX: Versus tie-in helped the publisher claim both Unit and Dollar share, with 38.64% and 35.32% respectively.
However, DC gained ground on its bitter rival to end the month with 36.72% and 32.73%, a 2.5% increase from April, Newsarama reports.
DC also dominated the graphic novels chart thanks to the launch of its 'New 52' collections. The publisher claimed six of the top 10 places, with Justice League Volume 1 taking the top spot.
Marvel took the top two places on the single issues chart with Avengers vs X-Men #4 and #3 respectively, but DC titles accounted for seven of the remaining spaces.
The comics industry saw a significant year-on-year rise last month, a 42% unit increase and nearly 44% dollar growth. However, May 2011 consisted of four weeks, compared to this year's five.