Left-back Saka and striker Eddie Nketiah netted inside 26 minutes as Arsenal’s much-changed lineup made a dominant start and fought off a late Bournemouth rally to secure a tie against third-tier Portsmouth back on the south coast.
Saka, 18, blasted the ball into the roof of the net from a tight angle after five minutes before his low cross provided a tap-in for Nketiah, who was recalled this month from a loan spell at second-tier Leeds United.
Bournemouth’s Sam Surridge scored in the fourth minute of added time to set up a nervous finale for Mikel Arteta’s side but the hosts could not find an equaliser and are left to focus on the battle for Premier League survival.
Arsenal’s first-half performance was eye-catching, with 22 passes leading up to Saka’s fine opening goal.
Arsenal boss Mikel Arteta felt his young side showed “courage” to overcame struggling Bournemouth at Vitality Stadium and set up an FA Cup fifth-round trip to Portsmouth.
“Mikel is trying to bring back the philosophy of the Arsenal way. We did that well in the first half, not so much in the second half,” Saka told BT Sport.
Bournemouth’s last-gasp goal them some hope, Simon Francis’ low cross eluding everybody and allowing Surridge, 21, to score his first goal for the club after a loan spell at Swansea City.
“We’re very disappointed. We gave it a good go in the end,” said Bournemouth manager Eddie Howe.
“It was just a poor start. Tough first half hour and we struggled to deal with their movement. We weren’t ourselves. But for the last 60 minutes we scrapped and almost got something in the end.”