SEATTLE — Deebo Samuel didn't hesitate when he was asked what was working for the San Francisco 49ers.
''Brock Purdy,'' Samuel said.
Purdy threw for 255 yards and three touchdowns, and the Niners never trailed in a 36-24 victory over the Seattle Seahawks on Thursday night.
Samuel had a 76-yard catch-and-run touchdown and finished with three catches for 102 yards for the defending NFC champions (3-3), who moved into a tie with Seattle (3-3) for first place in the NFC West after an uneven start to the season.
George Kittle added five receptions for 58 yards and two scores for the 49ers, who beat the Seahawks for a sixth straight time. Kyle Juszczyk had a late TD run, and he and Kittle both celebrated their scores by leaping into the stands to embrace their wives, who were sitting together in the first row.
Matthew Wright, who joined San Francisco earlier this week to replace injured kicker Jake Moody, had a trio of first half-field goals from 25, 41 and 35 yards.
''When everyone's on point and we're doing our thing, we're a hard team to beat,'' Purdy said.
Geno Smith passed for 312 yards and a touchdown but was intercepted twice, and the Seahawks lost their third straight after a 3-0 start under first-year coach Mike Macdonald.