The England goalkeeper looked his usual confident and assured self as the Hammers enjoyed their second victory over our west London rivals in the space of seven days following last week's fantastic Premiership win at Upton Park.
And there was more welcome news for watching Hammers boss Glenn Roeder, as club captain Steve Lomas also completed 90 minutes for the first time since his own return from serious injury.
The only goal of the game arrived after just six minutes. After John Moncur had been fouled on the edge of the penalty area, young midfielder Grant McCann beautifully curled a free-kick round the wall and past Chelsea keeper Rhys Evans.
With livewire striker Jermain Defoe looking dangerous alongside Paul Kitson in attack, it seemed likely that the home side would add to their score. However, a young and enthusiastic Chelsea side, managed by the equally enthusiastic former Hammers coach Mick McGiven, refused to allow their more experienced opponents time on the ball and chances in front of goal were few and far between.
West Ham's hopes of grabbing a second goal were then dealt a severe blow just 10 minutes into the second half when Moncur, booked just two minutes earlier for a foul on Keenan, was sent off by referee Perkin for another ill-timed lunge at an opponent.
With Chelsea offering hardly any threat in attack, though, there was no real need to introduce a more defence-minded player in place of one of the strikers and, led by Lomas, the 10 men dug in determinedly for the remaining 35 minutes to hold out for three points.
Lomas - although not quite near Premiership sharpness yet - was full of energy and determination right up until the final whistle, while James proved he is well on the way back to full fitness with a smart save in the 65th minute after spending most of the match as a virtual spectator.
Speaking just moments after the final whistle, the 30-year-old keeper said: "It was great to be out there again. The whole thing was about playing 90 minutes, having to make decisions and seeing how I was going to react to making those decisions.
"I can work on the shot-stopping and that kind of thing in training, so there is no worry there, it was just nice to be back in a match situation again.
"I'm feeling fine and I was happy with the way it went. Now I just need more games to improve my sharpness and we'll see how it goes."
Boss Roger Cross admitted afterwards: "I felt it was an ideal game for David James to come back into. It wasn't too frantic for him but he had a couple of shots to deal with and he was always mentally alive. There were a couple of balls over the top that could have caused problems if the keeper stayed on his line.
"But you know David, he was off his line quickly dealing with it. His reading of the game is excellent and he is like a sweeper at the back sometimes.
"With Steve Lomas, it's still coming. He's been out an awful long time and I was very pleased with his performance. He just needs more games now to build up his match fitness."
Of the match in general, Roger enthused: "I thought it was a good performance, especially in the first half when we played some real good stuff.
"In the second half we lost John Moncur after just 10 minutes and had to play for 35 minutes with 10 men but I was still pleased because the boys dug in and held on for the win.
"They were an enthusiastic side with some good players and that made us play at a high tempo, which is good for us. It pressures the players and tests them to see how good they really are.
"All in all, a good night. I pleased with the attitude of the players and it is always pleasing to pick up three points."
Team: James, Johnson, Song, Potts, Soma, Newton, Lomas, Moncur, McCann, Kitson, Defoe (Riza 75). Subs not used: B.McMahon, Garcia, Britton, Clark.