The forward struck a low shot beyond Portsmouth goalkeeper Paul Jones in the 90th minute to seal a 2-0 home win for his side in League Two on Saturday.
Shaq had been introduced off the bench barely three minutes before finding the net.
In the same division, goalkeeper Jordan Archer made his first league start for Northampton Town as they lost by the odd goal in five at Newport County.
Three goals down after 53 minutes, the visitors reduced the arrears but fell short of completing the comeback and County – managed by former Spur Justin Edinburgh – claimed maximum points.
Two of our players were in action in the Championship on Saturday, Alex Pritchard playing 75 minutes for Brentford in their 3-2 home win over Brighton & Hove Albion while Grant Hall started for Birmingham City in their 1-1 home draw with Leeds United – only to be forced off at half-time with a groin injury.
Elsewhere, Tom Carroll was on the bench for Swansea City in their 4-2 Premier League defeat at Chelsea while Kenny McEvoy was an unused substitute for Peterborough United as they battled out a goalless home draw with Notts County in League One.
Overseas action saw Lewis Holtby make his competitive debut for German side Hamburg in their 2-0 Bundesliga defeat at Hannover 96, while Grant Ward played 80 minutes for Chicago Fire as they drew 1-1 at home to Toronto FC in the MLS.
Grant won a penalty in the 56th minute with his side already a goal to the good, but Jeff Larentowicz saw his spot kick saved and the visitors grabbed a point a minute from time.