In a match full of thrills, interspersed with some poor handling and average decision making, the lead changed frequently before the break with the visitors leading 17-15 at half-time.
The win moved them into fourth position on the log - but with five more matches to be played this weekend, they are bound to drop down.
The Lions, until then, had given as good as they got, but were outplayed in the second half with a surfeit of possession going the way of Crusaders.
The match saw scrumhalf Jano Vermaak further enhance his credentials as a probable Test player with some good options, sharp breaks and especially his good defence.
The Lions started off at a tremendous pace, and twice came close to scoring.
Some great interplay had the Crusaders at sea, but the old malaise of not finishing after creating cost the Lions again - and it was the visitors who scored first after a move from 50 metres out. Lock Isaac Ross was the scorer, and deservedly so after some good handling and off-loading in the build-up.
Six minutes later, Vermaak, who was dangerous every time he touched the ball and was earlier denied, scored in the corner with a swallow dive after good play from firstly Andre Pretorius and then Louis Ludik.
Pretorius - not asking for the customary sand bucket for the first time one can remember - converted from the corner (7-7).
It was the Lions who scored next when former Horskool Monument flanker Johan van Deventer went around two would-be tacklers for a great individual try on debut.
At 12-7 the Lions looked good, but a charged down kick from fullback Ludik saw Saders flyhalf Stephen Brett collect for a converted try that put his team back in the lead at 14-12.
The Lions were under pressure at scrum time and the visitors had a slight grip on the game before Leon MacDonald put them further ahead after 32 minutes with a penalty (17-12). Three minutes later the lead was reduced by Pretorius after a Brad Thorn high tackle on the Lions flyhalf when the home side were on attack, and the sides went into the break at 17-15 to the Crusaders who had missed 13 tackles to six in this half.
It was all Crusaders for the first ten minutes after half-time, but some defiant Lions tackling kept them out with flank Ernst Joubert and replacement lock Gerhard Mostert outstanding in defence.
With Crusaders continuing their onslaught, with some good inter-passing, the Lions remained under the cosh into the fourth quarter. After 23 minutes of the second half, Thorn was on hand to take an inside pass and, with MacDonald’s conversion, Crusaders went 24-15 into the lead.
But it didn’t last. Lions lock Anton van Zyl charged down the sideline from 50 metres out, kicked ahead and with the ball staying infield but his heel seemingly on the touchline when he picked up, went over for a try that was adjudged good. Pretorius couldn’t convert (24-20).
The try glut continued as Crusaders replacement hooker Dan Perrin was gifted a soft try around the front end of the lineout for an unconverted try (29-20).
Most of the play and the pressure now came from Crusaders who had some 80 percent of the possession in the second half but they were unlucky not to add to their tally. MacDonald put it beyond doubt with a penalty three minutes before time.
Scorers:
Lions - Tries: Jano Vermaak, Johan van Deventer, Anton van Zyl. Conversion: Andrè Pretorius. Penalty: Pretorius.
Crusaders - Tries: Isaac Ross, Stephen Brett, Brad Thorn, Daniel Perrin. Conversions: Leon MacDonald (3). Penalties: MacDonald (2).