The Hawks needed a penalty shootout to beat United Services and secure a spot in the semi-finals of the Portsmouth Senior Cup
The teams were locked together at 2-2 after 90 minutes at Westleigh Park, with the Wessex League division one visitors pushing the reigning champions all the way.
Aaron Cosgrave gave the hosts a 20th-minute lead with a composed finish.
Services refused to give way, though, and James Franklin levelled on 35 minutes.
Three minutes into the second half Harry Potter stunned the Hawks with a shot that deflected past Ben Dudzinski in the home goal.
Cosgrave equalised in the 64th minute but Lee Bradbury’s men couldn't find another breakthrough before the final whistle.
In a tense shootout Josh Huggins scored the decisive spot-kick to send the Hawks through to the last four.
AFC Portchester joined the Hawks in the semi-finals after beating 10-man Hayling United 2-0 at the Crest Finance Stadium.
The Humbugs had a player sent off after just seven minutes following an aerial challenge.
On 25 minutes Stuart McConnachie gave the hosts the lead with a fine opportunistic finish.
With the visiting goalkeeper off his line, the full-back sent a first-time shot sailing over the stranded stopper and into the net.
Brandon Miller struck in the 70th minute after a long throw fell to him in the six-yard area to seal the Royals win.
A first-half Steve Hutchings penalty proved enough to take Moneyfields through with a 1-0 victory against Baffins Milton Rovers at Dover Road.
The skipper buried his 19th-minute spot-kick into the bottom left-hand corner.
Meanwhile, Horndean got back to winning way with a 4-1 success against Tadley Calleva in the Wessex League premier division at Five Heads Park.
A third-minute Simon Woods goal set Fareham Town on their way to an excellent 2-1 victory at Brockenhurst.
Dan Brock extended the Reds lead four minutes from time with the Badgers grabbing a stoppage-time consolation goal.
The Royal Navy crashed out of the Hampshire Senior Cup after falling to a 1-0 defeat to Sholing at the Victory Stadium.