Two superb goals by Paul Heatley helped sink Ballinamallard as Crusaders moved seven points clear of Linfield at the top of the Irish Premiership.
Shane McGinty gave the visitors a shock early lead at Seaview but the Crues hit back with three second-half goals to boost their three-in-a-row title hopes.
Jordan Owens tapped home an equaliser after 58 minutes before Heatley's stunning double in a four-minute spell.
A superb 70th minute volley broke the deadlock and a deft finish sealed it.
Stephen Baxter's champions have lost just two top-flight fixtures during this campaign, and haven't suffered a league defeat in 2017, but the visitors put that record under threat in the first half.
McGinty conjured up a great opening goal, his fifth of the season.
From Ryan Mayse's pass, McGinty's reverse shot from just outside the box beat Sean O'Neill in the Crues goal after 17 minutes.
Brush later turned Whyte's free-kick around the post to ensure 'Mallards held onto their 1-0 lead at the interval.
The introduction of sub David Cushley turned the game in favour of the champions.
With 58 minutes on the clock, his pin-point delivery from wide on the left was met at the far post by Owens who clinched his 17th goal of the season.
Momentum was with the Crues, and Heatley displayed stunning technique to put them in front on 70 minutes.
When 'Mallards failed to clear Owens' looping header, Heatley hit the ball left-footed on the turn and it flew across the goalkeeper into the far corner of the net.
He wrapped up the game four minutes later, Cushley again involved in the build-up, beating two defenders and dinking the ball over Brush to make it 3-1 for his 20th goal of the season.