Cameron McJannett's 92nd-minute equaliser snatched a point for Derry against Waterford at the RSC.
Waterford led 2-1 at the interval thanks to goals from Junior Quitirna and Greg Halford, which sandwiched a Danny Lafferty strike for the visitors.
But McJannett's close-range effort denied Marc Bircham’s side a precious win.
The point lifts Waterford above Finn Harps into eighth spot with three games remaining,
Derry stay fourth but their form over the last few weeks has been indifferent.
Waterford got off to the perfect start by taking the lead on four minutes. Jack Stafford's ball picked out the onrushing Quitirna and the midfielder fired home from just inside the box, giving City goalkeeper Nathan Gartside no chance.
Derry had a half chance minutes later as Joe Thomson broke from midfield but his powerful strike from 20 yards was straight at Waterford stopper Paul Martin.
The home side continued to push forward and went close to scoring a second on 26 minutes but Gartside did well to push away Cameron Evans' long-range effort.
Against the run of the play Derry levelled as James Akintunde's cross flashed across the six-yard box and Lafferty came in at the back post to fire home.
Waterford regained the lead on 39 minutes as Patterson's free-kick deep into the Derry penalty box picked out Anthony Wordsworth, who headed back across for an unmarked Greg Halford to nod home from ten yards.
City brought on Bastien Hery at the break for Evan McLaughlin but the ex-Waterford man miscontrolled on the edge of the Derry box and Niall O'Keeffe nipped into to feed Patterson. The left winger's angled drive was saved at the second attempt by Gartside.
On 83 minutes a superb free-kick routine on the edge of the Derry area saw Patterson's low strike fizz just past Gartside's right-hand post.
Minutes later Halford went close to sealing the points but his glancing header flew over the bar.
Some clever play by the home side in the closing stages ended with John Martin getting in behind the Derry backline, but his left-footed strike was saved by a diving Gartside.
On 92 minutes a Thomson corner wasn't cleared by the visitors and the alert McJannett was on hand to fire high into the roof of the net from close range.
Waterford: Paul Martin, Darragh Power (Kyle Ferguson 12), Cameron Evans, Anthony Wordsworth, Junior Quitirna (Isaac Tshipamba 50), John Martin, Niall O'Keefe, Ronaldo Green (Shane Griffin 66), Jack Stafford, Greg Halford, Phoenix Patterson.
Derry City: Nathan Gartside, Eoin Toal, Cameron McJannett, Ciaran Coll (Will Fitzgerald 59); Ronan Boyce (Jamie McGonigle 49), Jack Malone, Joe Thomson, Evan McLaughlin (Bastien Hery HT), Danny Lafferty (Patrick Ferry 85); James Akintunde, Junior Ogedi-Uzokwe.
Referee: Graham Kelly (Cork).
