Two brilliant second-half goals from Patrick Bamford saw Aitor Karanka’s side move clear at the summit, with the rest of the chasing pack aiming to close that gap later on Saturday afternoon.
However, it was not all plain sailing for Boro. Daniel Ayala gave the home side an early lead, but Championship top scorer Daryl Murphy equalised soon after with his 23rd goal of the season and the visitors went close to going ahead.
The Teessiders regained the lead through Albert Adomah, though, before Bamford’s second-half brace made sure of the points.
Boro were straight out of the traps and found the opener in the third minute after Jelle Vossen won an early corner.
Former Town midfielder Grant Leadbitter played a short corner with Adam Clayton, who clipped a perfect ball into the six-yard box where Ayala (4) glanced past Dean Gerken.
The Blues goalkeeper then had to be replaced by Bartosz Bialkowski following a collision with Ayala, resulting in a five-minute delay to the match.
Ipswich bounced straight back when they drew level just moments after the re-start. Dimi Konstantopoulos managed to get a hand to Jonathan Parr’s thundering shot, but the ball fell to Murphy and he poked in from close range.
The former Sunderland striker almost bagged his second of the game in the 22nd minute when Boro failed to clear a corner, and the Irishman’s shot was deflected on to a post before Konstantopoulos managed to gather.
But Boro regained the lead in the 30th minute after a well-worked set-piece fell to the winger and he drilled through a crowd of players past Bialkowski.
After an open and lively first half, the second half started sluggishly but Boro created a good opportunity eight minutes in.
George Friend played an impressive diagonal ball across field to Adomah on the right wing and his left-footed cross found Vossen, but he mis-kicked a shot at goal and the ball looped over.
But the home side got the third goal in the 64th minute when Vossen put Bamford through with a clever header, and the on-loan Chelsea man calmly rounded Bialkowski before rolling into an empty net for his 12th of the season.
And the 21-year-old got his second in the 79th minute with a superb individual effort. Leadbitter played the ball to Bamford and he dummied Tommy Smith, turning the central defender inside-out before he advanced forward and drilled low past Bialkowski.
Bamford should have completed his hat-trick with four minutes to go when Adomah raced clear and laid off for the striker, but he ballooned a right-footed effort over the bar.