This time Pool were up to the challenge as the Bees paid the price for their hectic season, with many of their players looking tired at times.
Hartlepool controlled a goalless first half, but only had a string of corners to show for it.
Playing into frequent blizzards, Brentford struggled to get the ball away and keeper Stuart Nelson tipped Tony Sweeney's early shot round the post.
Gavin Strachan's corner hit the bar, but the home attack got no closer as Adam Boyd went close twice and Micky Nelson had a header saved on the line by his namesake.
The game burst into life after the break, Brentford taking the lead on 50 minutes when Cup replay hero Isaiah Rankin pounced on a Richie Humphreys back pass that stuck in the mud to score an easy goal.
But four minutes later, Pool were level when the lively Joel Porter was fouled in the area by Darren Pratley and Boyd slammed in his 20th of the season from the spot.
On 74 minutes the home team were ahead as Boyd created the space on the left of the area and pulled the ball back for Eifion Williams to lash in his shot from 10 yards.
Brentford tried to come back themselves, but the game was becoming more and more difficult for them as they tired, and four minutes from the end Porter's latest dart into the area and his great pass saw Sweeney finish in style for his 12th of the season.
After two defeats in four days, including the Cup replay, Hartlepool have now won two on the bounce and are one of the form teams in the play-off zone.