During October, AMD processors were inside 49.8% of PCs sold in US retail stores compared to 48.5% with Intel chips, according to California-based research shop Current Analysis. The data include both desktops and notebook computer sales.

While AMD’s success in the US retail-store market is notable, Intel maintains its top spot in the overall US consumer PC sales, the research showed. That’s in large part to direct marketer Dell Inc, which sells more PCs in the US consumer market than anyone and exclusively uses Intel processors in its boxes.

Still, AMD is expected to continue to do well in stores throughout the holiday season. The well documented rumor that Wal-Mart will sell a $398 AMD notebook and desktop PC on Black Friday (the day after Thanksgiving, when US retail sales pick up) bodes well for AMD’s fourth-quarter results, noted the research firm.

AMD did the unthinkable by surpassing Intel in October, said Matt Sargent, Current Analysis director of research. Continuing to hold this lead in the holiday season would be a colossal win for the company.

AMD’s PC processors may have outsold Intel in the stores, but its 40.1% revenue share of retail-store PC sales trails that of Intel’s, which has 57.6% revenue share. The difference is due to the average selling price of Intel PCs being significantly higher than AMD PCs.

AMD’s share of unit sales in the US retail-store desktop market grew from 52% in September to 67.7% in October. In the retail-store notebook space, AMD’s unit share rose from 26.2% in September to 31.5% in October, according to Current Analysis data.