COLLINGWOOD'S Ben Reid continues to build his reputation as one of the game's emerging key defenders, after a standout performance against St Kilda's key fowards showcasing his improvement.

In combination with his fellow defender Chris Tarrant, Reid took on the Saints' tall duo of Nick Riewoldt and Justin Koschitzke. Reid stood Riewoldt for most of the night and often outmarked one of the great marking forwards of the game.

''It was a good battle. They are both really good athletes and they can both run really well for the size of them and everyone knows that Riewoldt is an endurance animal, so running with him is definitely a hard day at the office,'' Reid said after the gutsy win at Etihad Stadium.

The 22 year old was among Collingwood's best in the 19 point victory. He had 21 disposals, took 10 marks, and had seven rebound 50s.

Importantly, he kept Riewoldt to just two first half goals, and the Saints' skipper had just 10 disposals for the night. Koschitzke was kept to six disposals and two marks for the match.

Despite outmarking Riewoldt in several one-on-one contests, Reid said he had to focus on the challenge of playing on a champion.

''He got me a couple of times as well. It is always hard playing on a champion like that, but playing in the backline every week is a challenge,'' he said.

The match was Collingwood's hardest test in recent weeks, as the inform Saints attempted to continue their six game winning streak. It was a tough and intense first half, played under finals-like pressure in front of a big crowd.

''We came, then they came back at us. It was all about the ebbs and flows," Reid said.

"It was a great challenge, and just thankfully we got the four points. You can never feel comfortable against St Kilda, they bring their best footy for a full 120 minutes and we had to continue to fight to the end.''

Since breaking into the team at the start of the 2010 season, Reid has played almost every game over the past two years, including both Grand Finals.  Still just 22, he feels like he is still learning the art of defence.

''I feel like I am still developing and still working hard on my game, I really just look forward to the challenge every week,'' he said.

''One of the best things about being a key back is that you get to play on a great player every week, and you learn something every week.''

Collingwood coach Mick Malthouse is delighted with Reid's progress from junior forward into a key defender in the space of three years.

 ''Ben has been terrific for over two years. He came to us as a forward and just didn't quite cut it at the time. He went back and played almost a full year in the reserves as a key back and gained an enormous about of confidence out of that one year," he said.

''We were tempted time and time again to bring him up but I think our backline was pretty well structured at the time, but he found himself coming into the side pretty quickly in the end and staying in the side ... we have seen over 100 years of football, you recruit a forward and they become a very good back.''

Reid believes Collingwood's back six, built around the speed and carry of Leon Davis and Harry O'Brien as well as the strength of himself and Tarrant, is working well this season but still has room for improvement.

"As a back six we really pride ourselves on helping each other out. Leon and Harry always bring their running game - that is what we love about them, [and] Taz stops everything that comes in," he said.

 "It is a good group at the moment, but we are still working towards where we want to get to. It is just about improving our game and nailing everything we can. If we keep working on, it can only hold us in good stead in September."