Newcastle United substitute Alexander Isak headed home a last-minute winner to earn his side a 1-0 victory over Fulham at St James' Park on Sunday. The Magpies seemed to be heading for a third goalless league draw in a row when Callum Wilson forced Sean Longstaff's ball into box back across the six-yard box to leave Isak with a simple finish. But it might have been very different had Aleksandar Mitrovic not suffered a penalty nightmare against his former club. The big Serb slipped as he was taking a second-half penalty, kicking the ball against his standing foot before finding the back of the net, resulting in the goal being disallowed for a double-touch by Mitrovic. Victory means Newcastle, who will play Southampton over two legs later this month for a place in the League Cup final, leapfrogged Manchester United and moved back up to third in the table. “Certainly a crazy second half. A lot happened in it,” said Newcastle manager Eddie Howe, who included Joelinton in the starting XI despite his midweek arrest for drink-driving. “These moments can sometimes do that [galvanise you]. Something happens, a flash point, we didn’t concede. The crowd were really good for us from that moment on.” Fulham, who remain sixth, may feel hard done by after frustrating their hosts for long periods and threatening at times on the counter attack. “So many things to say about the ref's performance,” said Fulham manager Marco Silva. “But first I will say that I am really proud of the players and my team. We had ambition, quality, desire and showed why we are doing so well this season. “Credit to Newcastle, they are a really strong side as well. We missed a penalty and we should have attacked more. Credit to them for not giving us more chances.” In the first-half, it was the link-up between Longstaff, Miguel Almiron and Kieran Trippier down the Magpies’ right that caused Fulham problems. But it was a ball straight down the middle with six minutes of the half remaining that ended with Bernd Leno pulling off a good reaction save from Wilson after the striker had spun on to Fabian Schar’s pass. Newcastle suffered a blow when key midfielder Bruno Guimaraes turned over his ankle in the first half and left the pitch in tears after trying to play on through the pain. “Bruno was very distressed,” admitted Howe. “He was in a lot of pain. He twisted his ankle and felt he could run it off. In the end he needed to be withdrawn.” Newcastle defender Schar was unfortunate to see a 61st-minute free-kick come back off the post before Almiron’s shot from the rebound was scrambled to safety. However, Silva’s men thought they had taken the lead after they were awarded a penalty after a VAR review of Trippier’s challenge on Bobby Decordova-Reid. After a lengthy delay, Mitrovic sent the spot-kick past Nick Pope, but only with the help of a double-contact and referee Robert Jones swiftly ruled out the strike to hand the home side a fortunate escape. The deadlock was eventually broken with a minute of normal time to go when £60 million striker Isak headed home from point-blank range after Wilson had sent the ball back across goal.