In 1901, Hughes completed 32 of his 35 starts for Chicago, including innings pitched. Despite his 10–23 mark, in part due to low run support, he recorded a 3.24 earned run average while striking out 225 opponents, the third-best ever for a National League rookie. He jumped to the American League the following season, while dividing his playing time between Baltimore and Boston. In 1903, he became the third starter in the Boston rotation, behind Cy Young and Bill Dinneen. Hughes responded with a 20–7 mark and a 2.57 ERA, helping his team to clinch the AL title. He pitched in the inaugural World Series, losing Game Three.