They recorded a fourth straight success following a 22-16 victory at the Halliwell Jones Stadium against opponents who had won their last six Super League outings.
Tries from Robert Lui, Alex Mellor and Ash Handley put Leeds in control 20-6 at the break but they played much of the last ten minutes with just 11 men after the excellent full-back Liam Sutcliffe and Lui were both sin-binned.
Rhinos with Aussie forward Matt Prior immense, spent most of the second period defending but held on with a remarkable defensive effort.
“Fifteen minutes into the game, we were really struggling for energy - then at half-time we were full of it,” said Agar.
“As it was getting tight at the end, 20 minutes to go and Daryl Clark and Blake Austin are coming into the game and finding offloads, we were clinging on.
“We’d lost a couple of players with injury - Jack Broadbent and Mikolaj Oledzki - and then we were down to 11 men against a team like this so we were hoping and praying something went our way.
“We needed more control and coughed up some poor finishes but three games in nine days shows there’s a fair bit of spirit and courage in this team.”
Warrington had only scored one try until Leeds saw yellow.
Agar said: “I thought in the first half we were magnificent.
“In the second half, as the energy dropped out of the game, it was a bit like a game of touch and pass.
“We were clinging on and we had to hang on by our fingernails, for dear life.
“But we hung on and came up with some great last-ditch efforts.
“It was a magnificent effort from our boys.
“In the second half we didn’t turn the ball over on our terms, we turned it over early in sets, didn’t kick well and came up with some poor decisions, but I’m not too worried about that because we were doing it so tough energy-wise.
“To come here for our third game in nine days was an absolutely enormous task, but the spirit was fantastic and it shows what you can do when you’re working hard for each other.”
Leeds lost centre Broadbent after 15 minutes with an ankle injury while prop Oledzki needed a pain-killing injection in his foot to return and help Leeds get home.