SANTA CLARA, Calif. (Interstat) — Brock Purdy accounted for four touchdowns and the San Francisco 49ers held off a determined Arizona comeback to beat the Cardinals 36-30 on Sunday at Levi’s Stadium. Purdy completed 15 of 27 passes for 297 yards and ran twice for 34 yards for San Francisco, which improved to 3-0. Arizona dropped to 1-2. An announced attendance of 70,687 watched the 49ers build a 17-6 halftime lead and then survive Arizona’s second-half surge.

Purdy opened the scoring with a short pass to Mike Evans that turned into an 80-yard touchdown after Deebo Samuel Sr. took a lateral and raced down the left side. Eddy Pineiro’s extra point made it 7-0 with 8:26 left in the first quarter. Early in the second quarter, Purdy found Evans again, this time on a 23-yard deep pass to the right, and Pineiro’s kick pushed the San Francisco lead to 14-0.

Arizona answered with field goals on consecutive drives. Chad Ryland connected from 26 yards with 3:03 remaining in the second quarter, then hit from 41 yards with 23 seconds left before halftime. The Cardinals went into the break down 14-6. San Francisco added to its lead just before the half when Pineiro made a 57-yard field goal as time expired in the second quarter, sending the 49ers into the locker room ahead 17-6.

The 49ers extended their advantage early in the third quarter when Christian McCaffrey scored on a 1-yard run up the middle. Pineiro missed the extra point wide left, leaving San Francisco with a 23-6 lead. Arizona responded late in the third when Jacoby Brissett threw a 5-yard touchdown pass to Michael Wilson. Ryland’s extra point cut the deficit to 23-13.

Arizona kept coming in the fourth quarter. Brissett capped a drive with a 1-yard touchdown pass to Jeremiyah Love with 13:06 left, and Ryland’s extra point made it 23-20. San Francisco answered when Purdy found George Kittle for a 10-yard touchdown in the middle of the field. Pineiro missed the extra point off the right upright, keeping the 49ers ahead 29-20.

Brissett then scored on a 1-yard run up the middle with 2:51 remaining, and Ryland’s extra point brought Arizona within 29-27. San Francisco appeared to get a 45-yard touchdown run from Purdy on a scramble left, but the play was nullified by an offensive holding penalty on Kittle. On the next play, Purdy threw deep right to Kittle for a 20-yard touchdown, and Pineiro’s extra point made it 36-27. Ryland added a 49-yard field goal with 34 seconds left to close the scoring.

Purdy finished with four total touchdowns, completing 15 of 27 passes for 297 yards and adding two carries for 34 yards. Kittle caught six passes for 82 yards and two touchdowns. Evans had three receptions for 34 yards and a touchdown. Jordan Watkins added two catches for 60 yards for San Francisco. McCaffrey scored on a 1-yard run, and Pineiro made a 57-yard field goal while missing two extra points.

Brissett completed 38 of 52 passes for 280 yards with two touchdown passes and one rushing touchdown. He also ran four times for 4 yards. Love rushed 21 times for 90 yards and caught five passes for 19 yards and a touchdown. Wilson caught 11 passes for 89 yards and a touchdown. Trey McBride had nine receptions for 75 yards. Marvin Harrison Jr. added three catches for 40 yards, Kendrick Bourne had two for 22, Elijah Higgins had three for 20, Hunter Long had one for 5, and Tyler Allgeier had four for 10. Jalen Brooks returned five kicks for 128 yards.

San Francisco’s defense was led by Fred Warner, who made 17 tackles. Renardo Green had 13 tackles, Dre Greenlaw added eight, Ji’Ayir Brown had six, and Deommodore Lenoir and Jack Jones each finished with five. Marques Sigle, Garret Wallow and Malik Mustapha each had four tackles. Keion White and Ogbo Okoronkwo each recorded a sack. Upton Stout, Brayden Willis and KhaDarel Hodge each had two tackles. Sebastian Valdez, Gracen Halton and Khalid Kareem each had three tackles, while Naquan Jones, Osa Odighizuwa, Kevin Givens, Ashtyn Davis, Jaden Dugger and Luke Gifford each had one. Corliss Waitman punted three times for 145 yards. Kaelon Black ran four times for 17 yards. Siran Neal had two tackles and one punt return for no yards, Jacob Cowing returned one punt for 7 yards, and Luke Farrell had one tackle.

Arizona’s defense got 10 tackles from Andrew Wingard, eight from Jack Gibbens, six from Mack Wilson Sr., four from Max Melton and three from Zaven Collins. Elijah Higgins had two tackles on defense to go with his offensive work.

The result continued San Francisco’s unbeaten start. The 49ers had beaten Miami 35-13 in their previous game and opened the season with a 27-7 win at the Los Angeles Rams. Arizona had lost 31-7 to Seattle in its previous game after beating the Los Angeles Chargers 26-14. Purdy had completed 20 of 22 passes for 287 yards and accounted for three touchdowns in the win over Miami. Arizona will visit the New York Giants next Sunday, while San Francisco will host Denver next Sunday. Arizona’s upcoming schedule also includes Detroit, the Los Angeles Rams, Denver, Dallas, Seattle, the Los Angeles Rams again, Kansas City, Washington and Philadelphia. San Francisco’s upcoming schedule also includes Seattle, Washington, Atlanta, Las Vegas, Dallas, Minnesota, Seattle, the New York Giants and the Los Angeles Rams.

Interstat’s game simulator had projected a final score of San Francisco 33, Arizona 19. Interstat’s ELO system gave San Francisco a 96.7 percent probability to win. Arizona had been installed as a pregame favorite with a spread of +7.5. The total score of 66 went under the over-under line of 48.5.