The Benin international scored the only goal in the 1-0 victory over Everton at the Stadium of Light on Saturday to deliver back-to-back wins for new boss Paolo Di Canio
Sessegnon has scored seven league goals this season and eased the Wearside club's relegation fears at the Stadium of Light by securing a second successive win.
|4/6||Paolo Di Canio is 4/6 with BetVictor to be in charge of Sunderland at the end of next season
"Once we get him the ball in the right places he's going to hurt teams. To be fair to Sessy, the work he has been putting in in training in the last two weeks has been fantastic.
"I've seen him do it in training and his goal earlier in the season against Fulham was like that, he's more than capable of scoring from outside the box and hopefully there is a few more to come from him this season."
O'Shea revealed that new manager Paolo Di Canio had stepped up the intensity of Sunderland's training sessions since replacing Martin O'Neill and believes they are now reaping the rewards.
"The gaffer requires 100 per cent from everyone in the training sessions," the former Manchester United defender added.
"Everyone has been fantastic and now we're getting the rewards from it - we need to keep working hard."