Ritchie registered his fifth and sixth goals of the season to set the Cherries on their way to three wins out of four and secure their mid-table position.
The former Swindon ace opened the scoring after 50 minutes with a powerful effort past Marek Stech after a mazy run from Ryan Fraser.
Seven minutes later he had his second when a 25-yard curling shot deflected off Shane Duffy into the top corner.
Eunan O'Kane completed the scoring with his first ever Championship goal, sliding a left-footed effort past the diving Stech.
A happy Howe said: "Matt has added a huge goal threat and has done it all his career. Cutting in from the right he is a difficult man to mark and you can see his quality when chances are presented to him.
"We love him to bits, think he is a top player and hope he can stay in this goal-scoring form he is in.
"I was very pleased with the first-half performance and with the chances we created - I thought we were top drawer.
"In the second half we didn't hit the heights we did in the first, but scored three goals. In the end we won the game comfortably.
"It was really important today. The results have been disappointing but the performances have been good. They were a tough nut to crack."
It could have been worse for the Glovers but for an inspired first-half display from Czech goalkeeper Stech, who made vital saves from Ritchie, Lewis Grabban, Charlie Daniels and Fraser.
The away side managed to hit the upright twice through Ishmael Miller after 12 minutes and Ed Upson late on, but they were well beaten.
Manager Gary Johnson said: "If it does not continue to improve then of course we are going to be in trouble.
"We let them get their tails up and when we don't quite get our act together and we give the ball away then of course you are going to be in trouble anywhere in the Championship.
"We hope they are going to be learning very quickly because a couple of teams have done that to us this year and we haven't quite handled it.
"We had a bad day and we were second best. We have got to recover as that is the sort of game that could give you the feeling that could send you down.
"I apologise to our fans and am sorry we did not give them enough. Hopefully they will improve quickly and we have reacted well to setbacks in the past."