Valentin Castellanos scored an extra-time winner as West Ham edged out Queens Park Rangers 2-1 in the FA Cup third round.
The former Lazio striker, who arrived from Lazio earlier this week, netted his first goal for the Hammers, as they scraped past their Championship opponents at the London Stadium.
West Ham saw QPR goalkeeper Joe Walsh keep out Max Kilman's close-range header and Richard Kone clear Jarrod Bowen's header off the line, before they broke the deadlock in first-half stoppage time.
Ten additional minutes were played due to an injury to Konstantinos Mavropanos, who left the field on a stretcher, with Crysencio Summerville lashing home to ensure the hosts went into half-time with a lead.
The visitors responded in the 65th minute, with Kone outjumping Aaron Wan-Bissaka to nod home Karamoko Dembele's cross, and ultimately force extra-time.
Eight minutes had elapsed when Summerville turned provider for the winning goal, as his inviting centre was met by Castellanos' fierce header to take the Hammers through.
Elsewhere, League One Mansfield Town claimed the scalp of Championship side Sheffield United, holding on for a 4-3 victory having led 4-1 at Bramall Lane.
There were no such problems for Norwich City, with Jovon Makama's hat-trick helping them to a 5-1 rout of Walsall, while West Brom and Hull City advanced following penalty shootout victories over Swansea City and Blackburn Rovers, respectively.
Data Debrief: Summerville scores at last
West Ham ended a 10-match winless streak in all competitions, stretching back to a 3-2 victory over Burnley on November 8.
Meanwhile, Summerville halted his long wait for a goal, stretching back to October 2024 against Manchester United (28 games).
Mansfield have reached the FA Cup fourth round for the first time since the 2007-08 season, with this the first time they have beaten a side from the top two tiers at this stage since also defeating the Blades in January 1969.