The 25-year-old completed 25 of his 34 passes for 295 yards as the 49ers extended their winning streak to five games.
Advertisement
Running back Christian McCaffrey caught two of the touchdown passes as the 49ers beat a spirited Colts team.
Purdy became the first 49ers quarterback to throw five touchdowns in a game since the legendary Joe Montana in 1990.
The 49ers head into their final two games of the regular season, against the Chicago Bears and the NFC West leaders, the Seattle Seahawks, knowing that two wins will clinch the division title and home-field advantage in the play-offs.
The Colts’ fifth straight loss means they drop out of the AFC South title race, although they could still clinch a wild card spot.
The result also guarantees postseason qualification for the Buffalo Bills, Jacksonville Jaguars and Los Angeles Chargers.
Advertisement
The Colts opened the scoring when emergency quarterback Philip Rivers, 44, threw to Alec Pierce, who finished with four catches for 86 yards.
However, Purdy quickly took control of the visitors, throwing touchdown passes to Demarcus Robinson and McCaffrey in quick succession in the first quarter.
Although Rivers and Pierce combined again early in the second quarter to even the score, Purdy picked out George Kittle with an 11-yard pass to help the 49ers take a 24-17 halftime lead.
Purdy then found Jauan Jennings and McCaffrey on either side of a one-yard touchdown to Colts running back Jonathan Taylor as the 49ers maintained their lead.
Advertisement
With less than four minutes left, San Francisco linebacker Dee Winters returned an interception 74 yards for his team’s sixth touchdown to secure the victory.