The Cowboys amassed 481 yards against a crippled Baltimore defense and held the ball for more than 40 minutes. Dallas totaled 227 yards rushing, the most against the Ravens since the franchise arrived in Baltimore in 1996.
It wasn't enough. Jones' return put the Ravens (5-1) ahead 24-13 in the third quarter, and Dallas (2-3) never got even against a defense that lost cornerbacks Lardarius Webb (right knee) and Jimmy Smith (lower leg strain), along with middle linebacker Ray Lewis (triceps) and defensive tackle Haloti Ngata (knee).
Webb tore his ACL, a league source told ESPN NFL Insider Adam Schefter.
Lewis will have an MRI on his triceps Monday, a team source confirmed to ESPN's Ed Werder.
And Ngata sprained his MCL and will have an MRI on Monday, a league source told Schefter.
"They threw a lot of haymakers at us," Harbaugh said. "Our guys stepped up at the end and found a way to win the game."
After Dez Bryant scored on a 4-yard pass fromTony Romo with 32 seconds left to make it 31-29, the 2-point conversion pass zipped through the arms of the diving Bryant in the front left corner of the end zone.
Dallas recovered the onside kick, but Dan Baileywas wide left on a 51-yard field goal try with 6 seconds remaining.
"I felt we fought really hard and well through a lot of different adversities in all three phases," Cowboys coach Jason Garrett said. "(The Ravens) have been awfully good for a while. This team's been awfully good in this place for a while. We gave them everything they could handle."
Ray Rice scored two touchdowns and Joe Flacco threw for a score to help the Ravens secure their fourth consecutive victory and enhance their grip on first place in the AFC North. Baltimore's home winning streak is the longest current run in the NFL.