"It was an unbelievable feeling," Brown said. "It was my first walk-off hit in the major leagues and it is priceless."
Howard wasn't around at the end after he was lifted for a pinch-runner in the eighth.
Down to its last out, Washington tied the score on Chad Tracy's solo home run off Jonathan Papelbon with two outs in the ninth inning.
Howard got the Phillies started with a second-inning home run. He had gone 71 plate appearances since his last home run on May 29.
"It felt good," Howard said. "I have been trying to put together good [at-bats] and let the power come as it comes and get good pitches to hit, and I was able to get one and elevate it and put a good swing on it."
It was only Howard's eighth home run, but it shouldn't come as a surprise that it was served up by Dan Haren.
The Nationals righthander entered the game leading the National League in home runs allowed. That was No. 18 this season.
Howard finished the game 3 for 3 with two RBIs. He is batting .274. Howard is 14 for 36 (.388) with six RBIs in his last 11 games. The only thing that's been missing has been the power.
Howard has been playing on a sore knee and he doesn't like to use that as an excuse, but he admitted that he is banged up.
"I feel if you are out there, you should produce," Howard said.
Former Phillies outfielder Jayson Werth, who was greeted with loud boos, opened the scoring with a first-inning RBI single.
The Phillies went ahead, 3-1, on Delmon Young's two-run double in the third.
Steve Lombardozzi, who was 5 for 12 in the first three games between these teams in Washington this year, hit an RBI double down the first-base line to cut the lead to 3-2 in the fourth.
In the fifth, Howard's single plated Revere, who had singled and stole second, to increase the lead to 4-2.
This was John Lannan's first appearance since April 17, when he suffered a strained quadriceps tendon in his left knee.
He pitched five innings, allowing two earned runs on six hits. Lannan struck out four and walked one while throwing 92 pitches.
"It felt pretty awesome being out there," Lannan said.
Michael Stutes continued his impressive showing, lowering his ERA to 1.32 by throwing two scoreless innings of relief. Meanwhile, Mike Adams continued on the opposite track, allowing one run on an RBI single by Ian Desmond in two-thirds of an inning.
Antonio Bastardo ended the eighth by getting pinch-hitter Adam LaRoche on a grounder to second. But both teams scored in the ninth.
Contact Marc Narducci at firstname.lastname@example.org. Follow @sjnard on Twitter.