UFC 42: Sudden Impact was a mixed martial arts event held by the Ultimate Fighting Championship on April 25, 2003, at American Airlines Arena in Miami, Florida.

The event was broadcast live on pay-per-view in the United States, and later released on DVD.

[1] Headlining the event was a Welterweight title bout between Matt Hughes and Sean Sherk.

[1] Joe Rogan provided the lead commentary for this event and was joined on colour commentator by fighter Phil Baroni with further analysis by Eddie Bravo.

Albeit Ludwig was in the bottom position on the mat before the halt, the action continued standing up which prompted a rule change: the action should be restarted from the same position where it was halted.