Kitson and Lita put Boro 2-0 up before Patrick Agyemang pulled one back. But instead of folding under the pressure, Boro stepped up a gear and Lita hit the third before O'Neil and Yeates put the icing on the cake.
Rangers' promotion push is in danger of coming off the rails, however, with Jim Magilton's side having won just once in their last six outings.
The hosts were actually the livelier side in the opening stages with Wayne Routledge linking up well with Adel Taarabt, although the on-loan Tottenham star's finishing was wayward.
Home midfielder Mikele Leigertwood headed Ben Watson's corner over and eight-goal top scorer Jay Simpson fired wide.
But Boro looked dangerous on the break and Lita shot straight at Radek Cerny before, out of nothing, Yeates crashed a 25-yard shot against the crossbar.
Sean St Ledger forced a fine save from Cerny after being teed-up by Kitson, but the former Spurs goalkeeper could do nothing about Boro's opener on the half hour.
Fitz Hall was booked for a clumsy tackle on Yeates and O'Neil swung in the resulting free-kick which was turned in by the out-stretched boot of Kitson.
The on-loan frontman has managed just two top-flight goals since joining Stoke last summer, but he has no such problems in the Championship and grabbed his third in three games for the Teessiders.
O'Neil thought he had grabbed a second before the break with a superb long-range shot but Cerny pulled off a fine save.
But Boro did double their lead when Watson handled in the area three minutes after half-time.
The ball was bundled into the net but referee Phil Gibbs had already pointed to the spot, and the official avoided a potentially awkward moment when Lita blasted the penalty past Cerny.
Magilton responded with a double substitution which paid immediate dividends, Rowan Vine's first touch a cross to fellow sub Agyemang who swept the ball past Brad Jones.
But Lita struck again on the hour mark when he latched onto a mistake from Leigertwood, cut inside and rifled an unstoppable shot past Cerny.
Lita was denied a hat-trick when another drive crashed off the post but O'Neil was on hand to tuck in the rebound.
And Yeates wrapped up a convincing win when he broke clear, ignored Lita's pleas for a square pass and coolly curled the ball past Cerny.