Johnson was the hero with the winning strike in the 91st minute with Chris Wondolowski and Chris Pontius also scoring for the all-stars, and John Terry and Frank Lampard scoring for Chelsea.
"That's what coach brought me here for," Johnson said. "I was just trying to pay it back."
The MLS scored two goals in the final 20 minutes of the game at PPL Park -- the home of the Philadelphia Union.
Johnson scored in injury time, breaking free as he got a lucky bounce off the leg of Chelsea defender David Luiz and his shot floated past goalkeeper Ross Turnbull.
Pontius, who suffered a season-ending broken leg last September, was named the man of the match.
"I didn't think I would be here, to be honest with you, not with the way everything went," he said.
David Beckham, Dwayne De Rosario and Pontius combined for the MLS's second goal. Beckham made a long pass to De Rosario who threaded a nifty pass to the front of the goal to Pontius who beat Turnbull.
"I was just making a run and I was able to slot it home," Pontius said. "It is an honour to be out here and play against such a great team as Chelsea. I am just taking it all in."
This marked the first win for an MLS all-stars side against a touring English Premier League team in four years.
Manchester United defeated MLS 4-0 last year and 5-2 in 2010. An MLS team lost on penalty kicks to Everton in 2009 but the all-stars beat Chelsea 1-0 in 2006.
Former Manchester United star Beckham received a loud ovation when he left the game in the second half after setting up Pontius's goal.
Beckham is now heading to London to take part in Friday's opening ceremonies of the Olympics.
"I can't talk about exactly what I am doing but it is exciting and you can feel that excitement now," he said.
Chelsea are in the midst of a four-game USA tour that featured the first soccer match at the new Yankee Stadium against Paris Saint-Germain and also a final exhibition against AC Milan in Miami as a warm up for the forthcoming season.
Source: AFP
Source: AFP