Warrington: (22) 28
Tries: Bridge, Fa'afili, Bracek, Kohe-Love, Gleeson
Goals: Briers 4
Harlequins: (6) 22
Tries: Bradley-Qalilawa 2, Haumono, Randall
Goals: Paul 3
Warrington survived a late fightback by Harlequins to strengthen their place in the top six of the Super League.
Tries from Chris Bridge, Henry Fa'afili, Andy Bracek and Toa Kohe-Love gave the Wolves a 22-6 half-time lead.
But two Nick Bradley-Qalilawa tries and another from Chad Randall got Quins back in the game.
Martin Gleeson scored Warrington's fifth try before Paul Rauhihi was sent off for a high tackle, but the Wolves dug deep to secure the two points.
Warrington coach Paul Cullen "It was a real dig-in from the players in difficult circumstances. Our kicking game was a little bit flat in the second half and Harlequins ground their way back into it.
"It wasn't the prettiest win I've ever been associated with but it was a very important one.
"That was not as easy win against a tough and resilient side. We've worked hard enough to come away with two points."
Harlequins coach Brian McDermott "I would have accepted a point but we wouldn't have deserved it. Warrington deserved the win.
"We lost the game because of the way we started. We looked a bit down for the first 20 and didn't ask enough questions in defence.
"Warrington got out into a lead and were smart enough to keep out in front."
Warrington: Reardon, Fa'afili, M. Gleeson, Kohe-Love, Grose, Bridge, Briers, Leikvoll, Sullivan, Rauhihi, Swann, Wainwright, Westwood.
Replacements: M. Gleeson, Barnett, Wood, Bracek.
Harlequins: Sykes, Stewart, Smith, Gafa, Bradley-Qalilawa, Paul, Dorn, Heckenberg, Randall, Mills, Hopkins, Noone, Purdham.
Replacements: Budworth, Haumono, Williams, Tookey.
Referee: S Ganson (St Helens)