Full-back Sam Tomkins took over as Super League's leading tryscorer with his 14th of the season, while Blake Green and Jack Hughes also crossed, but it was Farrell who caught the eye with his treble.
The contest was over by half-time when the visitors led 30-0 yet Bradford did manage to get on the board in the 54th minute through Jarrod Sammut's try, with the same player converting his score.
Hooker Shaun Lunt scored two and made another in an eight try-romp as Huddersfield won a third successive match by beating Hull KR 50-30.
Huddersfield were 26-12 up at the break as the tries by Craig Kopczak and Lunt were added to by further scores from Michael Lawrence and Joe Wardle, with Danny Brough having also kicked a penalty. Rovers' first-half points came via Craig Hall, who dived over from Josh Hodgson's pass, and through former Huddersfield star Greg Eden, Michael Dobson converting both.
Hull KR pulled closer with Eden's second try soon after the break. Brough's cheeky kick-through on the hour put Scott Grix in for a simple score and soon after Hall set up Con Mika at the other end. Lunt's second try gave Huddersfield breathing space again and further tries from Brett Ferres and Wardle sealed victory. David Hodgson had the last word with a try in the left corner.
The boot of Brett Hodgson put a spirited Wakefield to bed this afternoon as his 76th-minute drop goal got Warrington over the line in a 41-34 win.
Tony Smith's Wolves had led 24-6 and 40-22 at the Rapid Solicitors Stadium, but the home side refused to lie down and came back to within six points as the clock showed five minutes left.
A catalogue of errors then let them down, though, with two-try Paul Sykes not finding touch with a penalty and then Kyle Amor giving away a penalty, setting up Hodgson for his nerve-settling contribution.
It was perhaps rough justice on Wakefield, but Warrington simply reaped the benefit of outscoring their hosts seven tries to six, with Ryan Atkins, Joel Monaghan and Stefan Ratchford all getting braces. Richie Myler scored the other try for the Wolves with Hodgson kicking 13 points in all.
Peter Fox scored two tries for the Wildcats with Reece Lyne and Kyle Wood also crossing over while Sykes' boot added 10 points to his two scores.