Last season's premiers moved seven points clear of third-placed Chelsea to ensure their status in the Champions League next season and defender Richards was elated to have completed the job.
"I wouldn't say it was a great performance but we got the job done in the end," Richards told ESPN. "West Brom came here and played some good football.
"We knew they would come here with nothing to worry about and no fear and they showed some good stuff tonight.
"We always want to play Champions League football and with Chelsea breathing down our necks - it was a must win game today."