The hosts were quickest out of the starting blocks but were up against a resilient side that held firm at the back for the entirety of the first half.
Jurgen Klopp's side mustered their first effort on the quarter-hour mark as James Milner's cross towards the back post found Daniel Sturridge, but the forward's volley bounced into the ground and over the bar.
The Reds were then handed a great opportunity to take the lead on the stroke of half time when Tommy Smith yanked Firmino down to the ground to concede a penalty.
Salah's spot kick, however, was kept out by Lossl before Jordan Henderson rattled the post with his rebound to leave Liverpool frustrated going into the dressing room at half time.
The hosts were effectively gifted their opener early in the second half when a ball over the top was headed backwards by Smith into the path of Sturridge, who calmly dinked an effort over Lossl and into the net.
With Huddersfield forced to chase the game, their previously steadfast defence would find itself exposed and prone to panic, and Liverpool took full advantage of this by applying more pressure.
The second goal came on the 58th-minute mark, courtesy of Milner's corner being coolly headed home by Firmino to put the hosts seemingly out of reach of their beleaguered opponents.
David Wagner's side could not muster efforts of their own to get back into the game and were finished off in the 75th minute through Georginio Wijnaldum, who collected Salah's pass, took a touch and rifled a shot into the top right-hand corner past the helpless Lossl.
The result sees Liverpool edge up to sixth place in the Premier League table, while the Terriers remain 11th in the standings.