Defender Johnson's long-range effort earned the Cobblers a 1-0 win at Dagenham & Redbridge on Saturday.
Northampton have now conceded only two goals in their last eight games.
"Chris has pulled off some unbelievable saves for us. We've probably got the best keeper in the league," Johnson told BBC Radio Northampton.
"But this win was a great team effort. Hopefully we can keep it going and move up the table to where we need to be."
Johnson, 21, is on loan at Sixfields from Middlesbrough until the end of the season.
Normally it goes over the bar but luckily it went in this time
John Johnson
"When I came here, Ian [Sampson] was massive on us defending as a team and stopping crosses," he said.
"We've done a lot of back-four work in training and it's paid off."
Reflecting on his spectacular goal to beat Dagenham, Johnson explained: "I just decided to shoot. Normally it goes over the bar but luckily it went in this time. I wouldn't mind a few more."
Northampton will look to make it 11 games unbeaten when they entertain Accrington Stanley on Tuesday (kick-off 1945 GMT).
Source: BBC Sport
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