Surrey 459 (Pope 117, Borthwick 83, Burns 66, Groenewald 4-85) beat Somerset 180 (Patel 6-5) and 210 (Hildreth 89*, Morkel 4-36, Dernbach 4-49) by an innings and 68 runs
Surrey routed Somerset by an innings with more than four sessions to spare to replace them at the Specsavers County Championship table.
Only James Hildreth, who finished unbeaten on 89, offered prolonged resistance to a rampant Surrey seam attack. It is the first time since 1958 that Surrey have won three games in succession by an innings and they went on to win the Championship that season as well.
The odds on a first title since 2002, which was when Surrey last won at Guildford, will have shortened after this impressive performance.
They set victory by taking five wickets in the first hour as Somerset, who resumed on 18 for 0, lurched to 69 for 5.
Morkel made the breakthrough with his first ball of the day, trapping Matt Renshaw lbw half forward for two. Dernbach then picked up the first of two wickets in his opening spell when George Bartlett drove loosely and was caught behind.
Ed Byrom could only fend off the next delivery - a well-directed bouncer from Morkel - to short leg then Dernbach pinned Tom Abell deep in his crease.
Rikki Clarke had Steve Davies held in the gully at which point Somerset had lost five wickets for 51 runs before Hildreth and Lewis Gregory dug in, either side of lunch.
They added 62 runs to raise Somerset hopes of a fightback before another well-directed short ball from Morkel broke the stand as Gregory edged low to Clarke at slip.
Dom Bess played down the wrong line and lost his off stump to Clarke but Josh Davey gave Hildreth good support in an eighth wicket stand of 62 although Davey rode his luck. Surrey were convinced he had been caught behind before he had got into single figures and he was dropped on 19 by Scott Borthwick at second slip.
Hildreth pulled offspinner Amar Virdi, who was being watched by England's chief selector Ed Smith, into the adjoining road for six and coped well with Morkel's pace but he ran out of partners. Davey eventually gloved another good lifter, this time from Dernbach, to wicketkeeper Ollie Pope and Tim Groenewald played on for a second-ball duck.
Morkel applied the final touch when Max Waller, batting as concussion replacement for Jack Leach, who had been struck on the helmet by the South African on the second day, edged another bumper to Pope.
Hildreth hit 13 fours and faced 127 balls but lacked support against a Surrey side who look well equipped to end their long wait for the title on this evidence.