Brown died in an auto accident early Saturday. Defensive lineman Josh Brent, who was driving, remained in jail in Irving, Texas, charged with intoxication manslaughter.
The Cowboys (7-6) learned about Brown's death on their flight to Cincinnati on Saturday. Coach Jason Garrett told his team that the best way to honor him was to play well in a game with playoff implications for both teams.
A late comeback was just enough to beat the Bengals (7-6), who had won four in a row and had a chance to move into position for an AFC wild-card berth with a victory.
Instead, Romo pulled it out with another late comeback, which has been the Cowboys' way while winning four of their last five games.
Romo threw a 27-yard touchdown pass to Dez Bryant with 6:35 to go. Anthony Spencer's sack of Andy Dalton forced a punt, and Romo completed four passes on the drive to Bailey's winning kick.
Defensive tackle Jason Hatcher held up Brown's No. 53 jersey on the sideline as the Cowboys headed onto the field to celebrate.
Romo finished 25 of 43 for 268 yards with a touchdown, an interception and three sacks. DeMarco Murray converted a third-and-5 play to extend the final drive and ended up with 53 yards on 21 carries.
Newcomer Josh Brown kicked field goals of 25, 33, 25 and 52 yards for Cincinnati, which wasted an opportunity to move ahead of Pittsburgh for the second AFC wild card.
Cowboys owner Jerry Jones described his team as "grieving" before the opening kickoff. Dallas played a sloppy game until the closing minutes nothing out of character there and had a few especially bad moments.
Defensive coordinator Rob Ryan went onto the field arguing for a holding call against the Bengals in the third quarter, and the officials penalized the Cowboys for unsportsmanlike conduct. Dallas also was penalized for 12 men on the field during the drive, which ended with Brown's third field goal and a 16-10 Cincinnati lead.
In the end, a defense that has allowed only three touchdowns in the last four games couldn't hold on. And the Bengals made it tough on themselves by using all three of their timeouts early in the second half, leaving them unable to stop the clock on Dallas' final drive.
Dalton was 20 of 33 for 206 yards with five sacks, one touchdown and an interception that Brandon Carr returned 37 yards to set up Murray's 1-yard touchdown dive in the second quarter.
Dallas 20, Cincinnati 19
Dallas 3 7 0 10 20
Cincinnati 10 3 6 0 19
Dal • FG Bailey 37, 8:36.
Cin • Hawkins 8 pass from Dalton (Brown kick), 6:41.
Cin • FG Brown 25, 1:39.
Dal • Murray 1 run (Bailey kick), 10:33.
Cin • FG Brown 33, 3:24.
Cin • FG Brown 25, 9:22.
Cin • FG Brown 52, 6:45.
Dal • Bryant 27 pass from Romo (Bailey kick), 6:35.
Dal • FG Bailey 40, :00.
Attendance • 63,590.
First downs 20 19
Total Net Yards 288 336
Rushes-yards 24-49 20-146
Passing 239 190
Punt Returns 2-4 1-(-3)
Kickoff Returns 1-14 3-65
Interceptions Ret. 1-37 1-0
Comp-Att-Int 25-43-1 20-33-1
Sacked-Yards Lost 3-29 5-16
Punts 5-33.0 3-45.3
Fumbles-Lost 0-0 0-0
Penalties-yards 6-49 8-70
Time of Possession 30:11 29:49
Rushing • Dallas, Murray 21-53, F.Jones 2-7, Bryant 1-(minus 11). Cincinnati, Green-Ellis 12-89, M.Jones 1-37, Leonard 6-20, Dalton 1-0.
Passing • Dallas, Romo 25-43-1-268. Cincinnati, Dalton 20-33-1-206.
Receiving • Dallas, Witten 4-62, Bryant 4-50, Austin 4-46, Murray 4-22, Harris 3-33, Ogletree 2-28, Vickers 2-18, Dunbar 1-6, Hanna 1-3. Cincinnati, Hawkins 6-44, Gresham 4-43, M.Jones 3-45, Green 3-44, Green-Ellis 3-13, Charles 1-17.
Missed Field Goals • None.