N.F.L. Playoffs Live Updates: Kansas City Wins in Overtime

Matthew Stafford celebrated after spiking the ball before the Rams successful field goal attempt ended Sunday’s win over the Buccaneers.

TAMPA, Fla. — Rams kicker Matt Gay’s kick sneaked inside the left upright as the game’s final four seconds ticked away, giving Los Angeles a 30-27 win over Tampa Bay on Sunday to reach the N.F.C. championship game, where they will host the San Francisco 49ers, who eliminated the Green Bay Packers on Saturday.

The Rams’ lead, which had ballooned to as many as 24 points, evaporated late in the game when Buccaneers running back Leonard Fournette scored the game-tying touchdown on the drive preceding the game-winning kick.

But Rams quarterback Matthew Stafford, after nearly losing the ball on first down, connected with Cooper Kupp on a 44-yard pass two plays later, then hustled his team to the line of scrimmage to spike the ball and set up Gay’s field goal.

Kupp led Rams receivers with nine catches for 183 yards, and Odell Beckham Jr. added 69 yards on six catches.

It was a decisive and swift series to end the game, and the only one that went the Rams’ way. Far too often this season, Stafford, despite his impressive passing numbers and arm strength, had hurt the Rams’ offense with costly turnovers, particularly late in games.

Stafford tied the Jaguars rookie Trevor Lawrence for the league lead with 17 interceptions this season, and his interception to end overtime of the Rams’ Week 18 loss to San Francisco gave the 49ers their playoff berth.

The Rams had traded precious draft capital to acquire Stafford ahead of this season in the hope that he could catalyze a Super Bowl run, but his propensity to turn the ball over followed him to Los Angeles after 12 seasons as the Detroit Lions’ quarterback, where he threw at least 10 interceptions in all but one season and never won a playoff game.

But in a crucial stretch, Stafford found Kupp on a blown coverage route. He did not hold the ball and play for overtime. He did not turn the ball over. And he bested the quarterback on the other side of the field, Tom Brady, who is much more accustomed to late-game heroics.

Stafford ended the day with 366 yards on 28 of 38 passing, and three total touchdowns.

“He certainly delivered in a big way today,” said Sean McVay, the Ram’s head coach, when asked if Sunday’s performance was the reason the team signed Stafford. “I’ve always had a lot of confidence in Matthew. That never wavered.”

It was Brady who threw the game’s only interception, ending the Buccaneers’ possession near the end of the first half, and it was Brady who lost his cool under pressure. In a disastrous first half, he was flagged for unsportsmanlike conduct for the first time in his career after complaining to the officials about being hit in the face by Rams linebacker Von Miller in the second quarter.

The flag came in the midst of Brady and the Buccaneers’ most productive drive of the game to that point. Brady had converted on second-and-17 from the Rams’ 50-yard line, finding Leonard Fournette for a 19-yard gain, but the drive stalled three plays later. Ryan Succop missed the 48-yard field goal attempt, leaving the score at 17-3. The Rams kicked a field goal and went into halftime up 20-3.

In an attempt to defend last year’s championship win, Tampa Bay returned all 22 of its starters from last season’s team, a first in the salary cap era. The Buccaneers re-signed Chris Godwin, one of the off-season’s biggest free agent targets, and also brought back Antonio Brown, whom Brady had lobbied for the team to sign last season.

Neither player was available to Brady in Sunday’s game, however, as Godwin tore an anterior cruciate ligament during the regular season and Brown was released by the team in December. Another of the team’s high-profile adds, defensive back Richard Sherman, was placed on injured reserve with an Achilles injury.

Those losses, coupled with the fact that the Buccaneers were without their All-Pro right tackle Tristan Wirfs, manifested in protection issues in the passing game and offensive inefficiency. Tampa Bay converted just three of 14 third downs.

But Brady has to this point in his career been the ultimate postseason advantage and, in the second half, it looked like the 44-year-old quarterback known for his late-game heroics could lead yet another dramatic postseason comeback.

The Rams extended their lead to 27-3 on Stafford’s 1-yard touchdown run at the beginning of the third quarter, and Tampa Bay struggled to respond with a field goal. But Kupp fumbled the first pass on the next possession, giving the Buccaneers new life and a short field.

Starting from the Rams’ 30-yard line, Brady orchestrated a seven-play touchdown drive that was punctuated when Fournette, playing in his first game since Week 15 after returning from injured reserve, punched the ball in from the 1-yard line.

The teams traded fumbles on successive plays to begin the fourth quarter, with Brady losing the ball after being hit again by Miller and Rams center Brian Allen fumbling the snap. Clinging to its two-possession lead, Los Angeles forced two Tampa Bay turnovers on downs late in the game.

With less than five minutes remaining, Brady heaved a pass to receiver Mike Evans, who was covered one-on-one by the Rams’ star defensive back, Jalen Ramsey. Evans hauled in the pass for a 55-yard score that cut the lead to 27-20.

Cam Akers fumbled on the Rams' ensuing possession, giving Brady another short field. He capitalized with another touchdown drive, punctuated by a Fournette run to tie the score, 27-27, with 42 seconds remaining.

But then Stafford took over and ended Brady and the Buccaneers’ season.

Brady finished with 329 yards on 30 of 54 passing, with one interception.

The loss brings questions about what lies ahead for Tampa Bay. In the week leading up to the game, as he has in previous postseasons, Brady fielded questions about whether he might retire after this season because his contract runs through the end of the 2022 season. After Sunday’s loss, Brady told reporters that he hadn’t “put a lot of thought” into how he’d approach this off-season.

Before Sunday afternoon, it may have seemed like he would have more time to confront the prospect. Stafford made sure he did not.