Adam Reach struck a second-half winner as Sheffield Wednesday beat Premier League opposition in the FA Cup for the first time in 27 years with a 1-0 win at Brighton.
Owls winger Reach smashed home a deflected drive from the edge of the box 25 minutes from time to earn the Sky Bet Championship side a narrow third-round success at the Amex Stadium.
Wednesday's previous win over top-flight opposition in this competition came courtesy of goals from Chris Waddle and Mark Bright at Wembley in the 1993 semi-final against city rivals Sheffield United.
However, a memorable day on the south coast was tempered by a suspected knee injury suffered by 12-goal top scorer Steven Fletcher.
Below-par Albion, last season's semi-finalists, could have few complaints about the result and rarely threatened to force a replay at Hillsborough before being jeered off by sections of the home support.
The Seagulls, sitting 14th in the top flight, made seven changes for the tie.
Alireza Jahanbakhsh again had to be content with a place on the bench following his stunning acrobatic equaliser as a substitute against Chelsea on New Year's Day, while veteran striker Glenn Murray was left out the squad amid rumours of January transfer.
Neil Maupay was the hosts' biggest threat in an uninspiring opening period.
The Frenchman saw a low shot repelled by the legs of Cameron Dawson, having earlier rounded the onrushing Owls goalkeeper before seeing his path to the unguarded goal blocked by the imposing figure of Dominic Iorfa.
Wednesday came into the match on the back of three successive defeats during the festive period which have dented their play-off aspirations.
Garry Monk's six changes included a senior debut for 19-year-old defender Osaze Urhoghide at right-back.
Stand-in Owls captain Fletcher almost put the visitors ahead just before the break, dispossessing Dale Stephens following a risky short goal-kick from David Button, only to see the Seagulls keeper make amends by tipping over his powerful strike.
Wednesday were dealt a major blow 10 minutes into the second half when Fletcher was stretchered off.
The Scotland international looked in considerable discomfort after staying down following a innocuous challenge from Gaetan Bong.
Monk's men soon shrugged off the significant setback to edge ahead 10 minutes later.
Massimo Luongo, who wasted a chance moments earlier, was fouled by Steven Alzate on the edge of the box and Reach drilled home from the resultant free-kick via a heavy deflection after the ball was touched to him by substitute Sam Winnall.
Albion were victorious in the previous FA Cup tie between the clubs, winning 2-1 against the Owls at Highbury to reach the 1983 final, where they were beaten by Manchester United.
Record signing Jahanbakhsh, the Seagulls' man of the moment following two goals in as many games, was thrown on to help find an equaliser.
The Iran forward attempted a repeat of his memorable overhead kick goal against Frank Lampard's Blues but completely missed the ball from a Pascal Gross corner and it bounced behind off Shane Duffy.
An expected onslaught from the hosts failed to materialise and the away side hung on to their slender advantage to the delight of almost 2,200 travelling fans.