CLEVELAND -- The Baltimore Ravens should breathe a sigh of relief more than celebrate.

In rallying from a 20-point first-quarter deficit Sunday, the Ravens bucked the trends to upend the Cleveland Browns 25-20 at FirstEnergy Field.

But the Ravens must learn a lesson: Their slow-out-of-the-gate performance might cut it against the rebuilding Browns and their 17 rookies. It won't, however, against the likes of the Pittsburgh Steelers, Cincinnati Bengals and New England Patriots. And it might not even be good enough next Sunday against the Jacksonville Jaguars.

If the Ravens want to be mentioned among the AFC's best, they'd better play more focused and with more urgency than they did in Cleveland.

"It wasn’t pretty. We weren’t perfect. We weren’t great," quarterback Joe Flacco said. "Do you want to play a game like that in September? Not necessarily. But every single game in January and come February, where we hope to be, is going to be like that. It’s going to be tough situations. That’s why, over the years, these games have taken us to that next level and has made us so mentally tough."

Flacco was off his game and nearly cost the Ravens with two interceptions. The defense nearly allowed the Browns to march down the field for the winning drive in the final minutes if not for the taunting penalty on Browns receiver Terrelle Pryor.

This marked the second-biggest comeback in team history. But this wasn't a scintillating comeback -- this was the Ravens' outlasting the Browns and capitalizing on their mistakes.

The Ravens won ugly and in unlikely fashion. Baltimore (2-0) won for just the fourth time in 24 games under coach John Harbaugh when trailing by at least a touchdown at halftime. The Ravens came away with their fourth win in 20 games when Flacco throws multiple interceptions.

But this was the Browns. The Ravens have owned them, especially in Cleveland, where they are 8-1 under Harbaugh.

How did the Ravens rally from the second-largest first-quarter deficit in franchise history?

It came down to Flacco's throwing downfield with great confidence. He averaged nearly 15 yards per completion on his final 25 throws despite struggling with accuracy and decision-making. Flacco's 28-yard completion to tight end Dennis Pitta set up Justin Tucker's 49-yard field goal in the fourth quarter. That gave the Ravens their first lead of the game as they scored the game's final 25 points.

"Nobody cracked. Nobody panicked. Nobody pointed their finger," Harbaugh said. "Guys got mad, sure. They should. But we started playing better football."

The Ravens look to go 3-0 for the first time since 2009 when they play at the Jaguars next Sunday.