In the first ever FA Cup meeting between the two sides, The U’s produced an historic giant-killing over The Magpies when Middlesbrough-born Joe Ironside punished calamitous defending on 56 minutes to send the travelling 4,830 supporters into delirium at a packed-out St James’ Park.
Initially, it was an anxious few moments for the Cambridge contingent following a lengthy VAR review, but once the goal was awarded, Mark Bonner’s side had the belief that they could pull off a monumental upset and continue their fairytale run in the 150th anniversary of the competition.
It’s the first time since 2015 that the visitors have progressed to the fourth round, while Newcastle frustratingly exit at the earliest opportunity for the eighth time in the last 15 years.
Kieran Trippier’s debut overshadowed by FA Cup embarrassment
Kieran Trippier only joined the club on Thursday, when he signed from Atletico Madrid for a fee of £12 million plus add-ons to become the Saudi-backed consortium's first signing, so it was a slight surprise to see the England right-back named in the starting line-up, let alone play the full 90 minutes.
With chairman Yasir Al-Rumayyan, Amanda Staveley and Mehrdad Ghodoussi all in attendance, along with 47,000 Geordies, to see the new recruit in action as Howe named a strong side, but even Trippier's presence could not stop an embarrassing defeat against a side which sits 16th in League One.
When The Magpies went behind, it was the 31-year-old who urged his teammates to remain calm, though his debut ended in bitterly disappointing fashion as Newcastle crashed out of the FA Cup at the first hurdle.
Trippier was seen at full time asking some of his teammates to stay and applaud the supporters in the Gallowgate who had stayed behind, but instead they went straight down the tunnel and worryingly it suggests that confidence is at an all time low.
While the signing of Trippier is an excellent addition to the squad, given the experience and leadership qualities he possesses, the new owners will know that he will not single handedly be able to fix The Magpies' defensive frailties during the second half of the campaign and centre-back reinforcements are very much a top priority in the January transfer window.
Since returning from injury in November, The Slovakian has failed to rediscover his form in between the sticks and it was another below par performance on Tyneside.
While Dubravka should have gathered the ball at the first attempt, instead he spilled it and was then robbed of the ball before Ironside pounced and helped Cambridge pull off an iconic third round upset.
However, the forward wasn't the only one who proved to be a thorn for The Magpies as goalkeeper Dimitar Mitov deserves plenty of recognition for his eye-catching performance as he made a number of high profile saves throughout the game.
After Mitov had earlier thwarted Allan-Saint Maximin and Jacob Murphy, the Bulgarian left his best save till last when he acrobatically denied Joelinton's powerful header in stoppage-time with a phenomenal right-handed save to earn a well-deserved clean sheet.
23 attempts without a goal, The Magpies need to sign a striker
Of the 23 attempts at goal, Newcastle registered nine on target, but a lack of cutting edge in attack will be a huge concern for the supporters.
There was more bad news after the match as Howe confirmed that Callum Wilson is ruled out for eight weeks with a calf injury so they will need to bring in a replacement ideally before the clash with The Hornets.
Saint-Maximin started in Wilson's usual position, but the Frenchman is naturally a winger so he is always going to prefer moving out wide.
In truth, Newcastle are without many options up front and now that their top goalscorer is out until March, who will lead the line for The Toon Army?