The Latvian defender's strike shortly after the break finally broke Doncaster's resistence, and he killed them off with a late header to add to Adel Taarabt's penalty as Rangers edged six points clear at the top.
Neil Warnock's side have yet to concede at home and, with seven wins and a draw from their first eight games, have made their best start to a season since 1947.
They endured a frustrating first half, but whatever Warnock said at half-time had the desired effect as the west Londoners finally clicked into gear after the break.
A pedestrian opening period did not spark into life until the 25th minute when Martin Woods' 25-yard free-kick was pushed onto the inside of the post by the diving Paddy Kenny.
The ball fell at the feet of James O'Connor, with Kenny still grounded, but the defender's goalbound shot was superbly cleared off the line by the sliding Clint Hill.
Rangers finally got a sight of goal after 36 minutes when Spurs loanee Kyle Walker overlapped down the right and and crossed for Jamie Mackie.
But the striker, who has scored eight goals in eight league games so far this season, saw his weak shot saved by Neil Sullivan.
Taarabt almost produced a goal for Rangers at the start of the second half, but his precise free-kick was headed over the top by Gorkss.
But the breakthrough eventually arrived in the 53rd minute when Gorkss met Akos Buzsaky's corner with another firm header.
His initial effort was blocked by Rovers right-back Mustapha Dumbaya, but the big centre-half reacted quickest to slam the loose ball past Sullivan.
Rangers midfielder Hogan Ephraim had the ball in the net in the 72nd minute but was just offside when he collected Taarabt's pass.
But the second goal did arrive in the 81st minute after Heidar Helguson was upended in the area by Sullivan.
Helguson got back to his feet and tucked the ball away but referee Roger East had already pointed to the spot.
Luckily for the official, Taarabt made no mistake with the penalty.
And Gorkss gave the scoreline a flattering look with a powerful header from Taarabt's corner two minutes from time to make the points safe and keep the Rangers bandwagon rolling.