The Baggies' goalkeeping coach spoke out on the former England international shot-stopper following his display at Anfield on Monday evening when he stopped 14 Liverpool efforts, including a Steven Gerrard penalty, from hitting the back of his net.
Late goals from Gareth McAuley and Romelu Lukaku sealed a 2-0 victory which ended a six-match winless run for Albion and subsequently leaves them on 37 points with 12 matches remaining.
With Premier League safety in touching distance, Kiely is looking for the team to try and push on towards the top six and he is in no doubt that the form of Foster will play a big part in that target.
He told the club's website: "Ben Foster is a top, top Premier League goalkeeper and it's a pleasure to work with him.
"When he plays like he did on Monday there's no limit to what he is capable of.
"His contribution to the game was really pleasing and sometimes as a goalkeeper you make plenty of saves and your team still loses so it was nice that his performance counted for something.
"The fact that his performance contributed to us going and winning at Anfield is a big, big deal, so it's really pleasing for all of us.
"This season started in August and for us to have the points total we have now, in what is an unbelievable league, is nothing short of absolutely tremendous and it's been a fantastic season.
He added: "Hopefully we are now able to build on that result when we play our next game against Sunderland."