Arsenal great Dennis Bergkamp paid tribute to Jose Antonio Reyes after the young Spanish striker scored twice in five minutes to sink Chelsea and keep the holders on course for a third successive FA Cup success.
Reyes blasted Arsenal level 11 minutes into the second half, seizing on a loose ball to stride forward and fire a 25-yard left-footer beyond keeper Carlo Cudicini.
The 20-year-old, in for the injured Thierry Henry, struck again five minutes later. He nipped behind Mario Melchiot to finish Patrick Viera's defence-splitting pass with another left-foot effort for the winner.
Bergkamp said: "He got us on the way back. His first goal was exceptional, a tremendous strike. His second was another really good one after an intelligent run on to a very good pass." Reyes' second demoralised Chelsea, who had led after a tight first half. A weak Joe Cole header held by Jens Lehmann was their only riposte. They lacked width in the closing stages and Frank Lampard had one of his quieter games.
Yet, at the interval, it seemed that the Blues would finally end their Arsenal hoodoo. Adrian Mutu fired them into a 40th-minute lead, beating Kolo Toure to shoot past Lehmann after Scott Parker returned the keeper's weak clearance.
Jimmy Floyd Hasselbaink, unmarked at the far post, had wasted a good chance from Wayne Bridge's centre and Jesper Gronkjaer had a headed goal disallowed for a debatable offside.
Arsenal's only threat had come from Ashley Cole, who forced a point-blank save from Cudicini after Bergkamp carved an opening.
Arsene Wenger's team stepped up a gear after the break. Skipper Vieira shook himself free from Parker's attention and drove them forward.
He said: "We showed good spirit. We kept a high tempo and kept up the pressure." Reyes did the rest.
So the Gunners' jinx on their London rivals continued. It was the fourth year in a row that Arsenal have defeated Chelsea in the FA Cup.
The West London side have not beaten Arsenal in an FA Cup tie since January 1947 in a total of 11 matches.
Meanwhile, Arsenal have not lost an FA Cup tie since their 2001 final defeat by Liverpool and now their fans have a new hero – two-goal Reyes.