But it wasn't over until a pass by Cleveland's Brandon Weeden from the Ravens' 18-yard fell incomplete on the game's final play.
Williams' key play came with the Ravens' holding a 16-10 lead with under a minute left in the third quarter. Weeden threw an out route to receiver Travis Benjamin, but Williams read the pass and jumped the route, taking the interception to the end zone.
It took Williams 22 starts dating back to last year, including the 2011 postseason, for him to record his first career interception. The interception was needed for Baltimore as Cleveland almost rallied back to send the game to overtime.
After running off 3:28 on its final offensive possession, and up 23-16, Baltimore was forced to punt with 1:13 remaining. Weeden then drove the Browns to the Ravens 33-yard line. A fourth down Hail Mary attempt fell incomplete, but an unnecessary roughness penalty on linebacker Paul Kruger gave the Browns one more play with two seconds left from the Ravens 18-yard line.
Weeden's final pass sailed out of the end zone, giving the Ravens their third win of the season.
The Ravens (3-1, 2-0) held a 9-7 advantage over Cleveland (0-4, 0-2) at halftime and began their first drive of the third quarter at their own 11-yard line. Quarterback Joe Flacco led the Ravens down to the Browns 1-yard line, with three receptions going to receiver Anquan Boldin for 60 yards. On third-and-goal at Cleveland's 1, Flacco faked a run to Ray Rice and rolled to his right. His intended target was tight end Dennis Pitta, who was covered. Flacco, facing Browns linebacker Scott Fujita in the flat, juked the defender and stepped into the end zone for a touchdown, which put the Ravens up 16-7.
Keeping Cleveland in the game was kicker Phil Dawson, who made kicks from 50, 51 and 52 yards away. His 52-yarder with 4:33 left to play in the game cut Baltimore's lead to 23-16.
Flacco finished the game 28-for-46 for 356 yards, a touchdown and an interception. Boldin led the Ravens in receiving with nine catches for 131 yards.
Notes: Flacco threw an interception in the first quarter from Cleveland's 10-yard line. It was the first time in 125 red zone passes that Flacco threw an interception. His last red zone interception came in December 2009 against Green Bay. ... Browns receiver Joshua Cribbs sustained a head injury during a punt return and did not return. ... The Ravens held a ceremony at halftime inducting former running back Jamal Lewis into the franchise's Ring of Honor.