An own goal from Nathan Jones and strikes by Jay Tabb and Turner cancelled out Matt Harrold and Lee Johnson's efforts either side of half-time.
Yeovil gifted Brentford an own goal for the opener in only the sixth minute. Jones was under no pressure to clear Paul Brooker's hopeful cross in to the box.
But the midfielder hopelessly headed the ball past his own goalkeeper Chris Weale and into the bottom left corner.
Their misery was added too seven minutes later when Tabb doubled the Bees' lead.
Tabb made the most of Yeovil's inability to clear their lines, picking up a loose ball in the box and firing it straight past Weale for his third goal of the season.
Before Tabb's strike Brentford went close through Dudley Campbell. The former Yeading striker first scuffed his shot wide and then had a good shot from the edge of the box saved by Weale.
Weale was also called upon to deny Brooker. The goalkeeper was quick off his line and made a brave save at Brooker's feet to prevent the midfielder a clear shot at goal.
Kevin Gall and Paul Terry both had chances for Yeovil, but saw their shots sail over the bar and easily saved respectively.
Brentford keeper Stuart Nelson was then called into action to save Chris Cohen's free-kick from distance.
The visitors did grab a consolation goal through former Brentford striker Harrold in the 37th minute.
Harrold followed up Johnson's shot to score from close range for Yeovil's first goal in four games.
Any hopes of mounting a comeback were dealt a massive blow when they were reduced to ten men after Weale was shown a straight red card for bringing down Campbell.
But against the run of play Johnson scored a spectacular equaliser from 25 yards.
Then right at the death Turner struck to earn Brentford all three points and extend their unbeaten run to six games.
Yeovil however, have suffered five straight league defeats.