The Reds were ahead in only the second minute thanks to Downing, who headed in from six yards after good work from the impressive Philippe Coutinho.
Thereafter it was all about Suarez, who put his side two up after another sublime pass from Coutinho, and then got his second via a deflected free-kick off the head of the unfortunate Shaun Maloney.
Any lingering doubts as to who would take home the points were firmly put to bed when the Uruguayan completed his hat-trick with ease to move his side up to seventh in the table, and leave the Latics languishing down in 17th.
The last thing that Roberto Martinez will have wanted was to concede early against the Premier League's top scorers of 2013, but in less than two minutes they did just that.
Coutinho was allowed far too much space on the left to pick out the run of Downing, who could not miss the header from six-yards out.
The Latics looked disjointed, and the frustration was clear to see as Gary Caldwell had to separate James McArthur and Emmerson Boyce who were having a heated discussion after yet more poor defending.
It wasn't long before Liverpool got their second thanks again to good work from Coutinho. The Brazilian playmaker carried the ball to the edge of the Latics' box, unchallenged again, and threaded a delightful pass through to Suarez, who passed the ball past Ali Al Habsi with consummate ease.
Just after Pepe Reina had spectacularly saved a Arouna Kone header, the in-form Suarez added a third from a far from clean cut free-kick. He slipped as he took it, it deflected off the head of Maloney on the end of the Wigan wall, and then Al Habsi will be disappointed he didn't keep it out after getting two hands to it.
Reina then produced another fantastic stop to keep out a Franco Di Santo header from point blank range to keep the deficit at three at the break.
Just as they did in the first-half, the Reds came out of the blocks quickest, and killed the game off four minutes into the second half.
Once again the Wigan challenges weren't forthcoming enough, and Glen Johnson was allowed space to carry the ball from the back, and play Suarez in, who could pick his spot to go two clear of Robin van Persie at the top of the Premier League scoring charts.
The rest of the game was a mere procession for Brendan Rodgers' side, who had chances to go further in front, but will be more than happy with the manner of their comprehensive win.