Young Crawley goalkeeper Freddie Woodman helped deny Portsmouth a third successive Sky Bet League 2 victory with several important saves as the teams fought out a 0-0 draw at the Checkatrade.com stadium.
Portsmouth came close to taking the lead after only nine minutes when a through ball from Nigel Atangana put former Crawley striker Matt Tubbs clean through, but he was denied by England Under 19 international Woodman.
The hosts did not threaten until mid-way through the half when Welsh winger Gwion Edwards headed over from a free kick by Luke Rooney.
Pompey midfielder Kyle Bennett put an angled shot over before a low drive by Rooney was held by keeper Brian Murphy at the other end.
A goal-bound header from Pompey's on-loan defender Matt Clarke was cleared shortly before the break following a corner to the back post by Gary Roberts.
Crawley came to life on 58 minutes when Edwards cut in dangerously and drilled a fierce low shot into the side netting.
But Pompey continued to dominate possession and keeper Woodman, on loan from Newcastle, was forced to parry a goal-bound low shot from substitute Adam McGurk.