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:
1. Derby 0 Middlesbrough 1 (13th) - 17/03/15
Boro moved back into the Championship's top two with just eight games to go after a 1-0 win over their promotion rivals. Patrick Bamford grabbed the only goal of the game midway through the second half. Photo: Laurence Griffiths
2. Liverpool 2 Middlesbrough 2 (12th) - 23/09/14
A night full of drama as Boro were eventually beaten 14-13 on penalties at Anfield. A stoppage-time equaliser from Bamford forced the shootout before Boro bowed out of the League Cup. Photo: Alex Livesey
3. Millwall 1 Middlesbrough 5 (11th) - 06/12/14
Rampant Boro ran riot at the Den as a Jelle Vossen hat-trick secured a resounding win. Photo: Jordan Mansfield
4. QPR 2 Middlesbrough 3 (10th) - 01/04/16
Goals from Jordan Rhodes, Gaston Ramirez and Ben Gibson secured a pivotal three points at Loftus Road as Boro took a big step towards Championship promotion. Photo: John Walton