Defeat would have left Real eight points off their rivals with 13 games remaining but Benzema buried a late strike to salvage a draw and keep the deficit to five points.
Luis Suarez struck for the home side in the first half and Diego Simeone's men looked set to take a giant stride towards winning their first title since 2014, but Zinedine Zidane's men had other ideas.
Suarez opened the scoring after 15 minutes in a crucial clash at the Wanda Metropolitano, with a fine effort using the outside of his boot, following good work from Marcos Llorente. The goal ended a five-game goal drought and marked Suarez's 498th for club and country in his career.
Zidane's side went into the match five points behind Atletico, who also have a game in hand, and the Madrid coach said the title race would not be decided by events on Sunday.
Real Madrid, second best for most of the first 45 minutes, called for a penalty late in the first half after Felipe appeared to handle in the area but following a VAR review, nothing was given.
"As always, I won't get into it," Zidane said of the appeal for handball and VAR ruling. "It's a difficult job. The referee looked at it and made a decision, we have to respect the decision and that's all.
"We know it's difficult. We know the rules, but it's the referee's decision. We have to respect that. It won't change. The players said it was handball, but the referee looked at it with VAR and decided not to give it."
The home side continued to force the issue in the second half, with Llorente and Yannick Carrasco both going close, while Suarez also called Thibaut Courtois into action in the visiting goal.
Benzema squandered a glorious opportunity to equalise 10 minutes from time but his effort was turned behind by Jan Oblak. The striker made amends, though, eight minutes later when he met Casemiro's pass to level it.
Barcelona are three points behind Atletico Madrid following Sunday's derby, and Simeone's side have a game in hand on them.
Captain Koke rued the late equaliser after his side had bossed the game.
"We were superior to them but they can score against you at any moment," he told reporters.
"We brought fresh players on and tried to add to our lead but we were up against a great rival who have a lot of power up front.
"We have never said the title race is over and we know it's going to go down to the wire but we have to now focus on Wednesday, when we have a chance to pick up more points and our rivals do not."
However, goalscorer Benzema took heart from the result and said the draw ensures the race for La Liga is not over yet.
"I think they were better in the first half and we were better in the second and this is a good point for us," Benzema said.
"The result means the title race is still on our minds."
Zidane added: "In the end, the most important thing was the second half, to change the game. It's a point, we're alive and we'll keep fighting.
"Our objective is [to win the league]. We know there's a lot of league left, a lot of points at stake, we'll fight until the end. Things can always change."