The Reds closed the gap on league leaders Chelsea to just one point with just seven games of the season remaining thanks to a tense 2-1 win over Sunderland on Wednesday night.
Goals from skipper Steven Gerrard and Daniel Sturridge put Brendan Rodgers' side ahead before Ki Sung-Yueng pulled a goal back to set up a grand stand finish.
But the Merseysiders held on to claim maximum points and defender Agger believes they are now capable of winning ugly with the title race set to come down to the wire.
"At the end of the day it was three points and that was exactly what we came for," the Denmark international said in the Daily Star.
"We wanted to close the game earlier - it was unnecessary to let them into the game.
"But sometimes it's like that and you have to defend and we did that.
"I think we had them under control in the first half, and we should have continued like that. But that's football. In the first half we were patient and we worked hard to break them down.
Striker Daniel Sturridge agreed with Agger's assessment: "In the first half we were patient and we worked hard to break them down.
"Our back four defended really well. They were fantastic. You have to grind results out sometimes.
"You have to do the dirty things to get the result you want and we got there in the end."