It may not have ended well for the Spanish boss, yet Karanka did guide Boro back to the Premier League after seven years out of the top flight.
We look back at Karanka’s best 13 games in charge of the Teessiders – scroll down and flick through our picture gallery to see the full list:
9. Brighton 0 Middlesbrough 3 (5th) - 19/03/20
The Championship's top two met just before Christmas yet the result was rarely in doubt. Kike, Daniel Ayala and Stuani got on the scoresheet as Boro produced an accomplished away performance. Photo: Justin Setterfield
10. Middlesbrough 3 Brentford 0 (4th) - 15/05/15
The Riverside was rocking as Boro advanced to the play-off final by sweeping aside Brentford 5-1 on aggregate. Photo: Laurence Griffiths
11. Manchester United 0 Middlesbrough 0 (3rd) - 28/10/15
Boro stunned United at Old Trafford to reach the quarter-finals of the League Cup. The Teessiders won 3-1 on penalties after Tomas Mejias saved Ashley Young's spot kick in front of 10,000 away supporters. Photo: Getty Images
12. Manchester City 0 Middlesbrough 2 (2nd) - 24/01/15
Another memorable game in Manchester when Boro knocked a strong City side out of the FA Cup. A stoppage-time finish from Kike sealed the win. Photo: OLI SCARFF