Somerset strengthened their grip on the LV= County Championship relegation clash with Surrey at Taunton despite a rain-shortened third day.
Lewis Gregory and Peter Trego struck twice each to reduce the visitors to 97-4 in the second innings - a lead of 32 - before the weather forced an early finish with just 29.2 overs bowled during the day.
Surrey started play on 13-0 but again their top order imploded, with Hashim Amla bagging a pair.
The start had been delayed by an hour by morning drizzle, but Somerset got an early breakthrough on the resumption as Championship debutant Dominic Sibley (12) edged Gregory to 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.
Watchful opener Rory Burns waited until the 12th over of the day before adding to his overnight score of five. At lunch he was on 25, with Vikram Solanki on 14 and the scoreboard reading 56-2.
The pair took the total to 84 in the shortened afternoon session before Solanki (36) played forward to Trego and edged another catch to Marcus Trescothick in the slips.
Burns' eight boundaries were some of the only positives for Surrey, but the batsman was visibly annoyed when he threw his bat at a wide delivery from Trego and edged a sharp chance to James Hildreth at first slip to depart for 40.
The catch was made all the more creditable by the fact that Kieswetter dived across Hildreth in an attempt to glove it, a move which might easily have led to the latter taking his eye off the ball.
Surrey were 97-4 at that point but with the spitting rain immediately beginning to fall more heavily, the players were forced off before new batsman Steven Davies had a chance to face a ball.
The weather closed in and play was abandoned for the day at just after 4pm. Somerset now face a race against time on the final day to turn their pressure into a vital victory.