Five minutes of stoppage time followed the end of a thrilling, fractious affair at Anfield. Young Liverpool substitute Carvalho, who turned 20 on Tuesday, extended his birthday celebrations with a 98th-minute winner. Extra time was added to extra time due to the treatment of Newcastle goalkeeper Nick Pope and time wasting by his teammates. Liverpool felt it poetic justice that victory should come with the last kick of a game often interrupted, but that did not justify the reaction of those on both ladders. Liverpool goalkeeping coach John Achterberg made a bee-line for the Newcastle bench after objects – perhaps water bottles – appeared to be thrown by staff in the visitors’ lounge. Howe’s side were under Liverpool’s skin throughout, with new record signing Alexander Isak scoring a superb opener on his debut, but thanks to sheer tenacity, willpower and excellence in front of goal , Jürgen Klopp’s team eventually prevailed. Liverpool will be hoping that winning ways will start their season. Newcastle will be hoping the nature of their first defeat doesn’t define theirs. With Callum Wilson, Allan Saint-Maximin and Bruno Guimarães out injured, and the Home Office clearing his work permit hours before kick-off, Isak was slotted straight into Newcastle’s starting line-up following his £63m move from Real Sociedad. Alan Shearer was in the directors’ box to watch the centre-forward’s debut and must have appreciated the emphatic, clinical way in which the Sweden international began his Newcastle career. Isak’s first goal came when he received Joe Willock’s pass on a counter attack, cut inside Joe Gomez and headed home from 20 yards. The striker, tireless in running, had to be patient for the next opportunity. He made the first payment of the record fee when he came. Liverpool were careless in the first half, resorting to punches and hope too often and were regularly opened up by Newcastle’s smart play. Discovery was a case in point. Trent Alexander-Arnold gave away possession on a miscued pass to Willock. Miguel Almirón and Kieran Trippier took over and when the full-back crossed low in the penalty area, Jordan Henderson’s attempted cut-back found Sean Longstaff. The midfielder pierced the Liverpool defense with an inch-perfect ball to Isak, who swept a stunning shot over the advancing Alisson and into the roof of the net. Alexander Isak celebrates with Joe Willock (right) after scoring on his debut. Photo: Serena Taylor/Newcastle United/Getty Images Klopp cut an increasingly angry, ferocious figure in the side. Referee Andre Marriner’s leniency, Newcastle players’ tendency to stay down for treatment and Liverpool’s performance could all be to blame. He was at one point against fourth official David Coote and was extremely lucky not to receive a yellow card. Isak believed he had doubled Newcastle’s lead early in the second half. His ‘second’ goal in black and white would have been superior to the first had it been confirmed. Released on the left by Ryan Fraser as the visitors caught Liverpool on the break, the forward raced into the area where he clipped Andy Robertson’s lamp, sold Gomez another dummy and beat Alisson with a thunderous shot once again. The assistant referee’s offside call was upheld by VAR, however, and Newcastle’s celebrations were silenced. Anfield grew increasingly restless as Howe’s determined side contained Liverpool with some comfort. The home side didn’t have a shot on target until Harvey Elliott tested Pope on the hour. However, that came amid a more urgent, penetrating spell from Klopp’s side, and moments later they equalized with a fine team goal. Newcastle’s resistance was broken with 10 touches and 12 seconds, the time it took from Alisson’s clearance at one end of the pitch to Roberto Firmino’s cool finish at the other. Henderson split the visitors’ midfield with a threaded pass to Elliott, who sent Mohamed Salah soaring into space against Matt Targett on the right. Salah produced a perfect assist in the box for Firmino and the Brazil international swept his shot low into Pope’s far right corner. Liverpool dominated the closing stages as Newcastle looked tired. The final act saw Gomez win a header from a corner, Longstaff and Willock fail to clear under Salah’s pressure and Carvalho sweep a loose ball into the roof of Pope’s net. Pandemonium ensued. Once more.