Joe Willock and Lewis Hall scored inside the opening seven minutes, and Newcastle held on despite being without nine players, with Hull’s Mohamed-Ali Cho pulling one back on 66 minutes.
Steur played almost 70 minutes at St James’ Park, and Jaissle said afterwards that the teenager had delivered a performance well beyond his years.
“He was outstanding, just like the other players were too.
“It was a performance you would expect from a really experienced, mature and seasoned player, but he is so young.
“We are emotionally stable, we give him and the other young players all the trust and support they need, and then he delivers like this.
“It’s really special. It’s not normal in football for such a young player, so I’m really happy.”
The result answered the heavy defeat at Leeds, and the injury list also grew when Tino Livramento pulled out of the England squad, but Jaissle was proud of the response.
“We were totally dominant and then in the second half you saw the legs were getting tired towards the end - but we were also missing nine players today.”
There was also encouraging news on Elanga. The Sweden winger has made a fine start to the season, scoring twice in three Premier League games, but was left out of the squad for Monday’s defeat at Leeds with a hamstring injury, and reports had suggested he could miss up to two months.
Sky Sports reporter Keith Downie now says the 24-year-old could be back after the international break.
“Anthony Elanga is making good progress in his recovery from the hamstring injury and there is hope that he can be back after the international break,” Downie said.
“Elanga underwent a new examination of the injury this week, but has been told he is making rapid progress.”
Elanga has scored eight goals in 34 caps for Sweden and previously played for Nottingham Forest and Manchester United. Newcastle United’s next league game after the break is against Coventry City on 12 October.