West Ham manager Sam Allardyce hailed a "massive victory" after Aaron Cresswell's first goal for the club proved enough to end Newcastle's winning streak at Upton Park.
The Irons moved back up to fifth place in the Barclays Premier League after a neat finish from left-back Cresswell, signed from Ipswich in the summer, proved enough to beat Newcastle 1-0, a side which came to east London full of confidence having won six successive matches in all competitions.
Any hopes of a comeback, though, disappeared after midfielder Moussa Sissoko was sent off late on for two needless quick cautions.
"It's a massive victory for us," said Allardyce.
"Newcastle have had the best run in the Premier League in recent weeks, even better than Chelsea which is saying something.
"I always thought it was going to be a tight match. I told the players it was about not conceding the first goal because if we did that it would have been difficult for us to get back into the game.
"To go back into fifth with 21 points gives us a huge push ahead of a massive week with three games in seven or eight days.
"At the moment we are achieving above expectations but it's vital, going into December, that we sustain things. Historically December and January have been difficult months for us in recent years."
The first half was devoid of much incident, apart from a claim for handball when former Magpies forward Andy Carroll crashed the ball at Mike Williamson, which looked to hit him on the underside of the upper arm, but referee Mike Dean was not interested.
The Irons, though, were ahead on 55 minutes.
Stewart Downing fed Cheikhou Kouyate at the edge of the box. His scuffed shot fell straight into the path of the on-rushing full-back Cresswell, who guided the ball into the bottom corner.
Allardyce said: "There is huge praise for Aaron for the quality of his finish. It was fantastic.
"He is a full-back and showed more attacking players how to put the ball in the back of the net today."
The visitors lacked a cutting edge in the final third, and had to play the final 15 minutes with 10 men after Sissoko collected two needless cautions in the space of as many minutes.
First the France midfielder kicked the ball away after a foul against him in the West Ham penalty area, and then had soon bundled into Carroll, who made the most of his reaction, as the referee reached for his pocket once again.
Newcastle manager Alan Pardew had few complaints with the sending off.
"Moussa was frustrated he has not got the free-kick in the box, and then just lost his mind a bit, with kicking the ball away and then in the next incident is just a minute after," he said.
"It is not like Moussa, he has been outstanding for us.
"He has to learn from this, but he is not a malicious player, although having seen it on the replay, it does not look good."
Pardew felt his team had worked hard enough, but just lacked their clinical touch of recent weeks.
"We did not really create the great moment we needed, although we got into some good positions, we could not find the great pass we needed, which we have done in recent weeks," he said.
"The goal we conceded was disappointing, having defended superbly against a team who put us under a lot of pressure.
"You kind of sensed that one goal was going to be important for both teams.
"Unfortunately today, we have just come up short."