Joe Ironside has 11 goals in 24 League One games this seasonJoe Ironside scored the winner as League One Cambridge secured a huge FA Cup upset by beating Premier League Newcastle at St James' Park.
The striker, who grew up idolising Newcastle legend Alan Shearer, turned in the winner from close range 11 minutes into the second half.
It proved a miserable Newcastle debut for Kieran Trippier, the defender signed from Atletico Madrid on Friday.
Goalkeeper Dimitar Mitov was superb as Cambridge saw out the win.
Mitov made a stunning stoppage-time save from Joelinton in as 5,000 visiting fans celebrated.
Those visiting supporters, high up behind the goal, were rewarded for their long journey north with a battling performance.
Though Mitov kept them in the game for long spells in the first half, they caused problems on the counter attack and defended superbly as the game went on.
Newcastle, without the injured Callum Wilson, looked devoid of ideas as a miserable campaign continued.
For the home support, it was meant to be a day of celebration following the arrival of new signing Trippier - but instead they fell to defeat, and remain with only one win to their name in all competitions this season.
Roared on by a near-sellout crowd, the hosts asserted themselves by dominating possession and pressing high early on. But Cambridge had a sight of goal within five minutes, when Adam May drifted into the box and struck over the bar.
Allan Saint-Maximin was heavily involved for Newcastle, who took just under 20 minutes to create an opportunity. The Frenchman met Jacob Murphy's cross at the back post, but couldn't keep his header on target.
Moments later, Saint-Maximin went close again as Newcastle began to turn the screw. This time, he couldn't guide Joelinton's scuffed shot goalwards, before feeding Murphy, who forced Mitov into a smart save.
Mitov was alert to deny Saint-Maximin and Murphy again, while Fabian Schar put the ball in the net for the hosts, only to be called offside. Murphy then had a shot tipped on to the bar just before half time.
Murphy thought he'd opened the scoring for Newcastle six minutes into the second half, but like Schar, he was denied by an offside flag.
Cambridge took the lead five minutes later through Ironside - a boyhood Sheffield United fan who grew up with Shearer as his hero.
Goalkeeper Martin Dubravka appeared to have smothered the danger as the visitors threatened his goal, but was then robbed of the ball and, after Schar failed to clear, Middlesbrough-born Ironside tapped home from close range - with the goal standing after a VAR check for a possible offside.
To sum up his heroic day, Mitov made a stunning save from Joelinton in stoppage time to clinch the win for the lower league side.
Line-ups
Newcastle
Formation 4-3-3
1Dúbravka
15Trippier17Krafth5Schär11Ritchie
8Shelvey7Joelinton36S Longstaff
21Fraser10Saint-Maximin23Murphy
1Dúbravka15Trippier17Krafth5Schär11RitchieSubstituted forManquilloat 78'minutes8Shelvey7Joelinton36S LongstaffSubstituted forAlmirónat 60'minutes21Fraser10Saint-Maximin23MurphySubstituted forWillockat 60'minutesSubstitutes
3Dummett16Hendrick19Manquillo24Almirón28Willock29Gillespie32Anderson56WhiteCambridge
Formation 4-2-3-1
1Mitov
2Williams15Okedina3Iredale11Dunk
4Digby27Worman
7Brophy19May26Knibbs
9Ironside
1Mitov2Williams15Okedina3Iredale11Dunk4Digby27WormanSubstituted forHoolahanat 61'minutes7Brophy19MaySubstituted forO'Neilat 90+5'minutes26KnibbsBooked at 66minsSubstituted forLankesterat 76'minutesBooked at 79mins9IronsideSubstitutes
8O'Neil14Hoolahan23Lankester28Bennett32Gill33Yearn35McConnellReferee:Tony HarringtonAttendance:51,395Live Text
Match ends, Newcastle United 0, Cambridge United 1.
Second Half ends, Newcastle United 0, Cambridge United 1.
Attempt missed. Miguel Almirón (Newcastle United) left footed shot from outside the box is high and wide to the right.
Substitution, Cambridge United. Liam O'Neil replaces Adam May.
Corner, Newcastle United. Conceded by Dimitar Mitov.
Attempt saved. Joelinton (Newcastle United) header from the centre of the box is saved in the bottom left corner.
Corner, Newcastle United. Conceded by Harrison Dunk.
Attempt blocked. Fabian Schär (Newcastle United) right footed shot from the right side of the box is blocked.
Foul by Emil Krafth (Newcastle United).
Joe Ironside (Cambridge United) wins a free kick in the defensive half.
Attempt saved. Emil Krafth (Newcastle United) right footed shot from outside the box is saved in the centre of the goal.
Attempt blocked. Jonjo Shelvey (Newcastle United) right footed shot from outside the box is blocked.
Attempt missed. Joseph Willock (Newcastle United) right footed shot from outside the box is too high.
Joelinton (Newcastle United) wins a free kick in the defensive half.
Foul by George Williams (Cambridge United).
Foul by Kieran Trippier (Newcastle United).
Harrison Dunk (Cambridge United) wins a free kick on the left wing.
Corner, Newcastle United. Conceded by Adam May.
Jack Lankester (Cambridge United) is shown the yellow card.
Javier Manquillo (Newcastle United) wins a free kick on the right wing.
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