Brook's 53 not out at Old Trafford helped drag the hosts within 60 runs of the tourists' first-innings total on Thursday.
He was still going strong in the middle with wicketkeeper Jamie Smith (22) after seam bowler Asitha Fernando had taken the wickets of Ben Duckett (18), stand-in captain Ollie Pope (6) and Joe Root (42) in England's reply to Sri Lanka's 236 all out.
It continues a strong start to Brook's Test career with the 25-year-old, playing in his 15th match, having already turned five of his fifties into centuries.
The Sri Lankans will not be without hope, though, knowing one more wicket takes them into the England tail.
Rain meant no play was possible before an early lunch was taken.
England resumed on 0-22 and there was early success for Sri Lanka after two DRS overturns in the space of three balls.
Dan Lawrence successfully reviewed an lbw decision to stay in the middle, only for Sri Lanka to review another lbw call that wasn't given against Duckett and get the left-handed opener out.
Pope was bowled two overs later, Lawrence edged behind off Vishwa Fernando for 30, and Root also nicked behind to wicketkeeper Dinesh Chandimal.
The fifth-wicket partnership between Brook and Smith is up to 51.
It's the first of three Tests between the teams, with England having already beaten the West Indies 3-0 earlier in the summer.
