Lewis Gregory and Peter Trego struck twice each as Somerset strengthened their grip on the LV= County Championship relegation clash with Surrey before being left frustrated on a rain-affected third day at Taunton.
The weather allowed only 29.2 overs to be bowled and they now face a race against time to press home their advantage, with Surrey 97 for four in their second innings, leading by 32 runs.
The visitors resumed on 13 without loss but again their top order batting imploded with Hashim Amla bagging a pair as Gregory grabbed two early scalps.
Rory Burns and Vikram Solanki offered some resistance with 40 and 36 respectively, but Surrey had good cause to be grateful when the weather intervened a hour after lunch, with both back in the pavilion.
The start of play had been delayed by an hour due to morning drizzle and Somerset needed an early breakthrough. It came when championship debutant Dominic Sibley hung his bat out tamely at a wide ball from Gregory and edged a comfortable catch to Marcus Trescothick at second slip.
Without addition to the total, Amla, who had been strangled down the leg side in the first innings, offered a more routine catch to wicketkeeper Craig Kieswetter in Gregory's next over.
The watchful Burns waited until the 12th over of the day before adding to his overnight score of five. At lunch he was on 25, with Solanki on 14 and the scoreboard reading 56 for two.
The pair took the total to 84 in the shortened afternoon session before Solanki played forward to Trego and edged another catch to Trescothick in the slips.
Burns blossomed to hit eight fours and was visibly annoyed when throwing the kitchen sink at a wide delivery from Trego and edging a sharp chance to James Hildreth at first slip.
Surrey were 97 for four and Burns' frustration could only have increased when the spitting rain immediately began to fall more heavily, forcing the players off before new batsman Steve Davies had a chance to face.
The weather closed in and play was abandoned for the day just after 4pm.