Middlesbrough moved out of the Championship relegation zone after two second-half goals gave Neil Warnock’s side victory at play-off hopefuls Millwall.
Ashley Fletcher raced away from the Lions defence and teed up Britt Assombalonga for a tap-in to open the scoring midway through the second period.
The hosts claimed a foul in the build-up, arguing Fletcher had tripped centre-back Jake Cooper while chasing a ball forward, but referee Tim Robinson waved play on.
Fletcher added a second from the penalty spot late on after being tripped by Cooper as the visitors secured their first win in three games.
The result lifted the Teessiders up to 18th in the table, and two points clear of the bottom three, ahead of the rest of the midweek fixtures.