Caron Butler added 23 points and 10 rebounds and Arenas had 18 points before leaving in the fourth quarter with a bruised left thigh.
"I wear pads, but for some reason I keep getting kneed where the pads aren't. Since I was sitting there, we went on a run," Arenas said. "Earl finished where I left off."
Did he ever.
Jamison, Butler and Boykins combined for a 9-0 run to make it 93-86 midway through the fourth. The points came just after Arenas drove hard to the basket and came crashing down after being whistled for an offensive foul for charging into Ersan Ilyasova.
He immediately reached for his leg where he's had three surgeries on his left knee in the last 1 1/2 years. He had a noticeable limp the rest of the way.
"I thought, 'This hurts way more than it should," Arenas said. "There was no point in putting me back in."
Jamison had a frustrating night in Tuesday's victory against Philadelphia, kicking an advertising sign along the baseline after all five starters were yanked for their play in the second half. But the Wizards battled back to salvage that game, and showed their composure after the Bucks rallied to take a fourth-quarter lead Wednesday.
"As long as I win that's all that matters. Last night was just a case of the ball not coming my way," he said. "Gil got it going early, Caron kind of got it going in the middle of the game and Earl and myself were able to finish it at the end. There are going to be times when you struggle."
Milwaukee trailed for more than 32 minutes before scoring the first nine points of the fourth, taking an 84-81 lead on jumpers by Charlie Bell and Kurt Thomas before Washington responded without Arenas, who has been the Wizards' best option recently.
Michael Redd scored a season-high 32 points for the Bucks, who have lost 12 of 16.
Redd reached double figures in less than 6 minutes and hit his first five shots from the field to finish the first quarter with 13 points, but he went into a deep slump after that, hitting one of his next 11 shots.
Charlie Bell scored 14 points for the Bucks, and Andrew Bogut had 12 points and nine rebounds after a career-best, 31-and-18 effort in a win over the Pacers on Monday night. It was Milwaukee's third straight home loss.
"At least we're consistent," coach Scott Skiles said tongue-in-cheek. "We play at home like we do on the road."
Bogut said he understood the coach's frustration and called the team's play demoralizing.
"I'm not sure if we were tired today or what it was, but we just weren't with it defensively at all," Bogut said. "We're through, how many games have we played now, 27 games, 100 practices and it's frustrating for everybody -- myself included. I made mistakes too. I can see why coaches are frustrated. There's not much to say after a loss like that."
Bucks rookie Brandon Jennings had the worst game of his young NBA career after getting into early foul trouble. He went 3 of 9 from the field for seven points and three turnovers in only 16 minutes.
"Disappointing loss," Redd said. "Their big three had a big night tonight, obviously, and throw Earl in there, too. Earl played well."
It appeared Jamison was credited for a basket that should have gone to Butler with 6:46 left in fourth. ... The Wizards, who shot 52.9 percent, almost became the second team in NBA history to fail to grab an offensive rebound since the stat began being kept in 1973. Washington finally got its only offensive board with 2:13 to play when Brendan Haywood grabbed one far away from the basket. ... The San Antonio Spurs did not have an offensive rebound in a win over Utah on Jan. 23, 2002.