Aleksandar Mitrovic came off the bench to cancel out Eric Dier's first-half opener before his fellow substitute Ayoze Perez netted a dramatic stoppage-time winner as the Magpies moved two points clear of the Barclays Premier League relegation zone.
McClaren, whose team also defeated Liverpool last weekend, said: "I thought the players were fantastic today. It's answered the critics we have had over last four weeks and it was a great performance in the second half and a great result.
"We have asked for consistency and the last two weeks they have provided that and it has brought everyone closer together.
"We kind of lost something in the international break and it's taken us two weeks to get that."