INGLEWOOD, Calif. (Interstat) — In a stunning upset that defied statistical projections and saw a dramatic fourth-quarter collapse, the San Francisco 49ers outlasted the Los Angeles Rams 26 to 23 in overtime on Thursday night at a stunned SoFi Stadium.

Quarterback Mac Jones, orchestrating a methodical attack, led the 49ers on a decisive overtime drive that culminated in a 41-yard field goal by Eddy Pineiro, handing the Rams their second loss of the season in front of a crowd of 73,652.

The victory improved San Francisco’s record to 4-1, while the Rams fell to 3-2.

The game’s outcome was a stark contrast to its beginning. The 49ers dominated the first half, looking every bit the team that was installed as an 8.5-point favorite despite pregame analytics from Interstat giving the Rams an 84.5 percent probability to win. San Francisco’s opening drive was a masterclass in efficiency, covering 75 yards in 11 plays and capped by a 6-yard touchdown pass from Jones to tight end Jake Tonges.

San Francisco extended its lead early in the second quarter. A 35-yard connection from Jones to receiver Kendrick Bourne set up a 1-yard scoring toss to Christian McCaffrey, pushing the lead to 14 points. The 49ers’ defense, led by linebacker Fred Warner and safety Marques Sigle, who combined for 25 tackles, stifled the Rams’ offense for much of the half.

Los Angeles finally found a rhythm just before halftime, with Matthew Stafford engineering a 10-play, 85-yard drive. He finished it with a 14-yard touchdown pass to Kyren Williams to cut the deficit to 14-7. The 49ers, however, answered with a two-minute drill, setting up a 37-yard Pineiro field goal as time expired to take a 17-7 lead into the break.

The third quarter saw both teams trade scores. Pineiro added a 20-yard field goal for San Francisco after a promising drive stalled inside the Rams’ 5-yard line. Stafford and the Rams responded immediately, marching 69 yards in just seven plays. Stafford found Puka Nacua for a 1-yard touchdown, bringing the Rams back within a score at 20-14.

The fourth quarter belonged to the Rams, who mounted a furious comeback. After a missed two-point conversion following Williams’ second touchdown catch of the game left the score at 20-20, the 49ers reclaimed the lead on a clutch 59-yard field goal from Pineiro with just under three minutes remaining.

With the game on the line, Stafford led the Rams on a desperate final drive. A key 20-yard run by Williams and critical completions to Davante Adams moved Los Angeles into field goal range. As time expired, Joshua Karty drilled a 48-yard field goal to send the game to overtime, deadlocking the score at 23.

San Francisco won the overtime coin toss and never gave the ball back to Stafford. Jones was surgical on the final drive, completing five consecutive passes, primarily to McCaffrey and Tonges, to move the 49ers into field goal range. A sack by the Rams’ Byron Young and Kobie Turner pushed San Francisco back, but Pineiro calmly nailed the 41-yard game-winner.

Jones finished the game with 342 yards and two touchdowns on 33-of-49 passing, effectively managing the game and relying heavily on McCaffrey and Bourne. McCaffrey tallied 139 total yards and a touchdown, while Bourne was a force with 10 receptions for 142 yards.

For the Rams, Stafford compiled 389 yards and three touchdowns on 30-of-47 passing. Nacua was his primary target, hauling in 10 catches for 85 yards and a score, while Adams added 88 yards on five receptions. Williams was a dual threat, rushing for 65 yards and adding 66 receiving yards with two touchdowns. Defensively, linebacker Nate Landman was everywhere for Los Angeles, recording a game-high 14 tackles.

The 49ers travel to face the Tampa Bay Buccaneers next on October 12. The Rams will head to Baltimore to take on the Ravens on the same date. The two NFC West rivals are scheduled to meet again in San Francisco on November 9.