The five-year-old with terminal cancer was the mascot at the Stadium of Light for the visit of the table-topping Blues.
Bradley, from nearby Hartlepool, has been told he’s got just months to live.
More than £700,000 has been raised to fund treatment in the USA after he was diagnosed with neuroblastoma in 2013.
But his mum Gemma revealed last week that the cancer had grown and any treatment would now just give Bradley more time.
Bradley’s cause was highlighted earlier this year when he was the mascot for Sunderland’s game against Everton.
He told his parents it was his dream to score at the Stadium of Light and tonight his dream came true.
“Cancer victim Bradley Lowery fulfilled a dream by scoring for Sunderland against Chelsea”
Dressed in a signed Black Cats shirts, Bradley knocked the ball around with star players Diego Costa and Jermain Defoe before the game.
And then he stepped up and fired home a penalty past Chelsea keeper Asmir Begovic.
Bradley also led the two sides out onto the pitch for the crunch Premier League game and supporters inside the stadium burst into a round of applause in the fifth minute in tribute to Bradley’s brave fight.
Sunderland have already helped Bradley this Christmas by sending him to Harry Potter World.
The youngster has also received more than 11,000 cards from wellwishers all around the world.