In the final midweek match of the tour, the Lions produced an efficient performance to give them a boost ahead of the two remaining Test matches against Australia.
Connor Murray got the ball rolling in the first half with Sean Maitland adding a second. Owen Farrell converted both scores for a 14-0 interval lead.
In the second half, the impressive Sean O'Brien crossed for a third try and although a couple of chances went awry, Warren Gatland's side sealed the win with a penalty try and an individual effort from replacement scrum half Ben Youngs.
Farrell converted O'Brien's score with his replacement Stuart Hogg putting the gloss on the win.
What would have pleased Gatland was his side's tenacity in defence, the Lions knocking back the Rebels time after time with skipper Dan Lydiate and countryman Toby Faletau to the fore.
After Maitland had come close to scoring from a Brad Barritt grubber, Murray opened the Lions account, diving over from the base of a scrum. Farrell converted and with Jason Woodward missing the chance to kick a penalty for the Rebels, Maitland then added a second try.
It was a superb team score, Manu Tuilagi showing his power to break through and offload to the Scottish winger. Maitland found the outstanding Faletau in support but with the Welsh No. 8 looking certain to score, he slipped on his approach to the line. Fortunately, the ball was recycled and Maitland finished it off in the right corner.
Farrell converted and nearly created a third with a quick tap penalty in an impressive first half performance. The English fly half played the game on the front foot, constantly testing the Rebels defence.
And although the Australian side had a period of pressure at the end of the first half, they opted to put a kickable penalty into touch. Ian Evans stole the line out though and their chance of points was lost.
Lydiate had led the Lions defence superbly in the first half, making 11 tackles in the first 40 minutes alone. Despite their deficit, former Wales man Gareth Delve was leading the Rebels well and he showed his commitment by winning his side a penalty from a line out early in the second half.
It wasn't long though before the Lions added their third, O'Brien scoring from a well worked short line out move.
Farrell added the extra two before being replaced by Hogg with 52 minutes on the clock, the Glasgow man then moving to full back minutes later as Billy Twelvetrees came on at No. 10.
The changes in the back line were irrelevant to the fourth try though, a huge shove from the Lions forwards taking them over the line. Rory Best looked certain to score and when Jordy Reid pulled down the maul, referee Glen Jackson, formerly of Saracens, awarded a penalty try and showed Reid a yellow card.
There was still time for another substitute to make an impression. From a line out to the tail, Youngs showed a trademark turn of pace to make it to the line with Hogg converting both scores to seal the win.