The versatile defender had spent large parts of the game standing the Eagles' man mountain, Quinten Lynch, in what appeared to be a physical mismatch.
Lynch stands 194cm and weighs in at an imposing 103kg; Richards is just two centimetres shorter but conceded nine kilos to his opponent.
Compounding matters was the fact that Lewis Roberts-Thomson, the Swans' most likely alternative for Lynch, left the field early in the final term with a hamstring complaint.
"I was just praying that it wasn't going to come back down my end," Richards said when asked of his thoughts during the tense last quarter.
"It was incredibly frustrating at times when we had the lead and they came back, but as much as that's annoying when you're playing full-back, it probably makes for good football to watch.
"To be honest, though, I'd rather if they weren't close and we just got a good lead and managed to hold on to it."
With West Coast fielding a tall forward line of Lynch, Ben McKinley and Josh Kennedy, Richards said the Swans' focus was to reduce that trio's opportunities from marks inside 50.
It was a task easier said than done with Lynch, Richards readily admitted.
"The thing with him is that he's almost always within goal-scoring range. The only time when he's not is probably when he's in defensive 50," he said with a laugh.
"If he's within 100m of the goals, he's a chance of having a kick. You can't lay off him at all. He moves well for a big bloke too."
The Swans boast an array of defensive options, from agile half-backs Marty Mattner, Rhyce Shaw and Paul Bevan to mobile talls Craig Bolton, Richards and Roberts-Thomson.
Richards said that the group's flexibility allowed the back six to find the most appropriate physical match-up and from there, they simply backed each other to do the job.
No doubt that's a tough ask when the likes of Geelong's Steve Johnson has a day out (see round seven) or Josh Kennedy creates some havoc with his strong marking (round eight).
"We all know our roles and certain defenders are suited better to certain forwards. We just really back our defenders to beat them," Richards said. .
"We stuck with the like-for-like [against West Coast]; we weren't going to start putting talls on smalls or anything like that. We won some contests and they won some contests, but we didn't try to change it too much."
