A combination of some superb goalkeeping from Derry No.1 Ger Doherty and some wasted efforts by Pat's denied Liam Buckley's side the win they craved.
That reminded some Saints fans of their fears in pre-season that, without a proven goalscorer in the side, the team would struggle for goals this season, and of the 12 league goals scored by the Saints this season, only one has come from a striker (Flood).
As he prepares to face up to one of his former clubs tonight in a game refixed from its original March date, Flood says the Saints players can't ignore the lessons from Friday's draw.
"It was disappointing to only get a draw against Derry on Friday as we had more than enough chances to win the game," Flood told the Herald.
"We were camped in their half for the second half but didn't get the win, so that means we need the win here against Bohs tonight.
"A point against a decent Derry side is not a terrible result. We got four points off the top two of Sligo and Derry in the space of a week so that's not bad, but we should have won the last game – apart from their goal I don't think Derry had a shot on target and our 'keeper Dave Ryan had nothing to do.
"We dominated in the middle of the park and created chance after chance but we didn't put them away and if we do that every week we will struggle.
"It happened us a lot last year – we were on top in lots of games but didn't have enough about us to win them and we had too many draws. Friday was our first draw of this season so we'll have to be sharper against Bohs," added Flood.
The Dubliner, one of a handful of players to have lined out for Dublin's big four (Pat's, Bohs, Shelbourne and Shamrock Rovers) knows what sort of threat the Gypsies will pose at Richmond Park, as Flood was at Bohs in the 2011 season when current Bohs stars like Roberto Lopes, Stephen Traynor, Keith Buckley and Ryan McEvoy were starting to emerge.
"I know how they'll approach the game with us – they will come to Richmond Park looking to beat us as they have nothing to lose," says Flood.
"We have to make sure our work-rate is good enough to overcome them and then convert our chances.
"We have a couple of hard games ahead of us. We had a lot of home games recently but the next two after Bohs are away, hard games against Cork and Drogheda, so if we can win tonight we'll definitely stay in touch."
Bohs come to Inchicore with legs a bit weary – this is their fourth game in 13 days – but with some of the gloom lifted as Aaron Callaghan's side ended a three-game losing streak by beating Bray Wanderers 3-2 on Friday night, where Chris Lyons, returning from injury after a five-week absence, inspired Bohs to a win with his two-goal contribution.
Callaghan switched to a three-man defence for the Bray game and that ploy, along with the introduction for the first time this season of Shane Fitzgerald and Andy Mulligan, helped the Gypsies pull off that win.
"We're going over there more confident as result of that win," said Callaghan.