The hosts opened the scoring inside the opening 10 minutes as Nick Blackman crossed the ball in from the right for Sa to hit first time from close range.
Ipswich were back on level terms just three minutes later as Ryan Fraser carved out some space in the Reading box before seeing Jonathan Bond parry it straight into the path of Freddie Sears, who tapped in on the rebound.
The Royals soon restored their advantage though as Sa scored his third goal in two matches for team, unleashing a long-range drive to beat Dean Gerken.
Christophe Berra had a chance to level again soon after as he got forward to try to head the ball past Bond, before Sears tried to force in his second, only to slice the ball over.
Reading started to look the more likely again as half time approached, with Matej Vydra trying to control a long ball forward on his debut for the hosts, but he was unable to create anything from it.