It was the first win for the Tigers in the far north since 2000.
The first try of the match, scored by Tigers' winger Jason Moodie, came just before the break and the visitors held an 8-2 lead at half time.
The turning point came just after half time when Wests Tigers scored again through Shane Elford and they suddenly held a handy 12-2 lead.
The Cowboys fought back numerous times but were frustrated by some determined try saving defence from the Tigers.
The win however may have come at a cost for the Tigers with confirmation that Benji Marshall has dislocated his shoulder.
The injury, suffered in the 17th minute, saw Marshall forced from the field and he is now in doubt for next weekend's Easter double header at Telstra Stadium.
Scorers: COWBOYS 8 Tries: Sargent Goals: Hannay 2/2 defeated by WESTS TIGERS 18 Tries: Moodie 2, Elford Goals: Hogdson 3/5
Dairy Farmers Stadium Referee: Shayne Hayne Video Referee: Mick Stone Touch Judges: Rod Lawrence, Steve Nash
By the clock: 0 min: Kickoff!
4 min: PENALTY GOAL - Tigers. Brett Hodgson puts Wests Tigers on the board from right in front. Cowboys penalised for laying on the tackled player. Tigers 2-0
9 min: PENALTY GOAL - Cowboys. Josh Hannay locks it up with a goal from just left of the uprights. 2-all
12 min: PENALTY GOAL - Tigers. Hodgson no mistake from right in front. Follows penalty for stripping after Benji Marshall (Tigers) comes close to scoring. Tigers 4-2
17 min: NEWS - Benji Marshall (Tigers) comes off with a shoulder injury and looks to be in some discomfort. Possible dislocation and unlikely to return.
32 min: No change to score. Cowboys with a big chance and an overlap but Ty Williams knocks on under pressure.
34 min: Cowboys get their second penalty of the match. Previously 6-1 favouring Tigers and the crowd giving referee Shayne Hayne a gob full.
36 min: NO TRY - Cowboys. Paul Bowman denied following a cross-field bomb. Bowman ruled to have knocked on. A let off for the Tigers.
38 min: TRY - Tigers. Jason Moodie finishes off beautifully to score out wide. Conversion attempt Hogson unsuccessful. Tigers 8-2
HALF TIME: Tigers enjoying a favourable penalty count but still doing most of the tackling; and struggling a little to get some momentum going. Scott Sattler and John Skandalis stand outs for the Tigers in both defence and with hit ups.
The Cowboys with plenty of chances but unable to finish. Keeping their opponents honest with some strong defence. Mathew Bowen making some great yards and Paul Bowman also a stand out for the Cowboys.
Second half underway...!
43 min: TRY - Tigers. Shane Elford scores out wide. Started with a tremendous break from replacement Robert Farrah who found Sattler in support. With more support play, the ball was kicked through. Cowboys fullback Matt Bowen made a meal of it - the Tigers scoring almost immediately after the break. Conversion Hodgson unsuccessful. Tigers 12-2
52 min: NEWS - Winger Ty Williams (Cowboys) intercepts, gets into open space and looks certain to score only to brought down by a sensational covering tackle from Tigers' forward Daniel Fitzhenry.
54 min: TRY - Tigers. End-to-end stuff as a failed intercept attempt from Ty Williams sees winger Moodie eventually score for the Tigers. Conversion Hogdson. Tigers 18-2
65 min: No change in the score. Cowboys getting repeat sets but the Tigers line holds firm. Tigers forced into a drop out but the Cowboys lose the ball in the next set.
72 min: The Cowboys again look likely to score following some enterprising play from Aaron Payne, only to be stopped by some desperate Tigers' defence, this time from Jason Moodie. Cowboys then cruel any opportunity with a poor last tackle option... a turn over again.
75 min: TRY - Cowboys. Mitchell Sargent scores. Follows another classy attacking movement being frustrated by some determined Tigers' defence. Finally, with a Tigers player (Scott Prince) down in back play, the Cowboys get through courtesy of a kick into the in-goal and the video ref gives the Cowboys their first try. Conversion Hannay. Tigers 18-8
FULL TIME: Tigers deserving victors - the turning points being just before and after the break with a tries in the 38th and 43rd minutes.
----------------------------------------- Leagueunlimited.com players of the match: 3 - S Sattler (Tigers) 2 - J Skandalis (Tigers) 1 - M Bowen (Cowboys) -----------------------------------------