Despite their 3-1 defeat at Burnley on Tuesday night, the Teessiders are 10 points clear of the drop zone with just four games left to play and all but assured of their place in next season's npower Championship.
That is a significant achievement for Mowbray, who inherited a team in serious danger of sliding into League One when he replaced Gordon Strachan at the helm in October.
Gibson told the club's official website: "The problem in football is that most appointments are made because the previous manager has failed, so most come in with the club under some duress.
"I knew what a difficult job it was, so when I spoke to Tony, he was given one remit - and that was to prevent the club from being relegated to the third tier.
"He has done a fantastic job to get us from where we were to where we are, to get us so far clear of the bottom three with still a few games of the season to go."
Source: PA
Source: PA