The big win saw Boro move to within five points of sixth place, as they look to make up the ground with just nine matches of the season left to play.
Speaking after the game, Lilywhites boss Alex Neil hit out at the officials for sending off midfielder Alan Browne in the first-half, after he had the last word in an off-the-ball scrap with Sam Morsy.
Neil claimed: “It’s an extremely poor decision. I have seen it back. Sam Morsy hits him with his forearm on the back of his head, he is right in front of them.
“Alan instinctively reacts because not only has he been hit once, it’s twice. It is hard to accept and understand how the ref and assistant can see Alan’s part but not Sam Morsy’s part. It changed the game in their favour. Their player is the aggressor and our player reacted in that instance.”
Next up, Boro will look to continue racking up the points this weekend, when they travel to take on Millwall in the capital.
Here are today's biggest transfer stories and the latest team news involving Middlesbrough and the rest of the Championship, as the build-up to the upcoming weekend's action begins:

. PRESTON, ENGLAND - OCTOBER 22: A general view of the EFL matchball prior to the Sky Bet Championship match between Preston North End and Leeds United at Deepdale on October 22, 2019 in Preston, England. (Photo by Lewis Storey/Getty Images)
Championship transfer news. (Photo by Lewis Storey/Getty Images) Photo: Lewis Storey

. Robins join McPake chase
Bristol City have been tipped to battle QPR for Rangers prospect Josh McPake. The Scotland U19 international is currently on loan with League Two side Harrogate Town, who are on-track for a solid mid-table finish. (Football Insider) Photo: Ian MacNicol

9. Boro could re-sign former starlet
Middlesbrough are believed to be keeping an eye on Sunderland striker Charlie Wyke, who continues to impress for the Black Cats with 21 goals so far this season. He came through Boro's youth academy, but never made a senior appearance. (FLW) Photo: Justin Setterfield

10. Hammers learn Browne asking price
Birmingham City are rumoured to have set a £1m asking price for their promising young defender Rico Browne. Spurs and West Ham were both linked with the teenager earlier in the month. (The 72) Photo: Clive Mason