Eastern Conference leaders Washington have continued their best start to an NBA season in seven years with a 104-92 road win over struggling Orlando.
Dinwiddie's double-double included a game-high 23 points and career-high 11 rebounds, while Montrezl Harrell added 20 points.
Aaron Holiday moved into Beal's starting spot and contributed 11 points on 5-of-9 shooting as the revamped Wizards, who traded Russell Westbrook to the Los Angeles Lakers during the off-season, extended their winning streak to four games.
Wasington - who have kept their past four straight opponents to less than 95 points - have improved to 9-3 to match the the start of their campaign in 2014-15.
"I'd rather be where we are than not," first-year Wizards coach Wes Unseld Jr. said.
"You just have to fight that temptation to get complacent.
"It hasn't come easy, and I give our guys credit because we've found ways on nights to eke out a win.
"But we can't sit here and say, 'We're good'."
Elsewhere, Miami snapped a three-game losing skid and swept the season series against Utah with a 111-105 victory.
Australia's Joe Ingles managed just four points on 1-of-5 shooting for the Jazz, who lost for the fourth time in five games.
Cleveland rallied from 19 points down in the third quarter to beat Boston 91-89 in a win sealed by a pair of Dairus Garland free throws with 9.4 seconds left on the clock.
Philadelphia lost a fourth-straight game without Joel Embiid after he tested positive for COVID-19, the 76ers going down 118-113 to Indiana.
Justin Holiday scored a season-high 27 points off the bench for the Pacers.
Nickeil Alexander-Walker scored 21 points as New Orleans snapped a nine-game losing streak with a 112-110 win over Memphis.
The victory was the first at home this season for the Pelicans, who had lost 12 of their first 13 games playing without Zion Williamson, sidelined with a broken right foot.
In anther upset, Detroit won 127-121 at Toronto.
with AP and Reuters