The Capitals went 2-for-2, and decided to score some too.
Washington's third victory in 12 games ended a three-game losing streak. They remain last in the Eastern Conference, however.
"Every game we're feeling more comfortable," Holtby said. "We learned a lot from the start of the season and there's nothing but good things going forward."
Friday, GM George McPhee told reporters, "The two areas we must get better is, keeping pucks out of our net, and it starts by not taking penalties."
The players also got together to address their slow start.
"We kind of had a team meeting; we could press the reset button and calm down a little bit," said Joel Ward, who had a goal and an assist.
The Capitals took three minor penalties (one coincidental) and a fighting major. The Panthers managed three shots on their two power plays, and Holtby stopped the other 24 for his first shutout of the season, fourth of his career.
"Tonight is a game that we need to model the rest of our season after," Brouwer said. "Everything was working in our direction because we were working hard."
Washington capitalized on a Florida mistake to take a 1-0 lead late in the first period.
The Capitals opened a two-goal lead in the second.
Holtby launched a pass from in front of his net to Brouwer at the opposite blue line. He skated to the right-wing circle and blasted a shot over Theodore's glove 3:26 into the period.
"That's a big goal; great play, big goal," Capitals coach Adam Oates said. "... It's a very heady play by him (Holtby). Pass down the ice -- that means he's involved in the game."
Later, after a five-man battle along the left-wing boards, the puck hopped to Ward's stick, and his shot found the net at 11:55.
Mathieu Perreault made it 5-0 when he whacked in a long rebound off a shot by Jeff Schultz. The goal with 10:32 remaining knocked Theodore, the Capitals goaltender from 2008-10, from the game with 16 saves. He was replaced by Scott Clemmensen.
Perreault, who also had an assist, had been a healthy scratch the prior five games.
The Panthers had won three of four with an overtime loss after a five-game losing streak. They sit in 13th place in the East.
"They were obviously a desperate team, but at least we could have made a game out of it," Panthers defenseman Brian Campbell told the Miami Herald. "The frustrating part is, we didn't give ourselves a chance and we've done that too many times this season. We knew they would come out and needed the points as bad as we did. We needed to match them. We didn't."
The teams have two days off before playing again in Florida on Tuesday.
Material from team media and wire services was used in this report.