Borthwick gives Surrey the edge on steamy day
Somerset are up against it in the clash of the top two after a tough first day at a new-look Guildford
Surrey 351 for 5 (Borthwick 83, Pope 73*, Burns 66, v Somerset
Surrey's top four built a solid platform as Somerset were left to regret their decision to bowl first in the top of the table Specsavers County Championship clash at Guildford.
Rory Burns (66) and Scott Borthwick (83) made half-centuries and Arun Harinath and Ryan Patel both contributed 48 before Ollie Pope hit an undefeated 73 as Surrey closed on 351 for 5 on a ground which has benefited from a GBP £2m makeover..
Cloud cover and a green-tinged pitch encouraged Somerset to bowl first and their seam attack kept plugging away in steamy heat. On another day they would have enjoyed more success as the ball frequently beat the bat.
But there was little to encourage their two England spinners Dom Bess and Jack Leach, who was back in their side five weeks after breaking his thumb, although Bess did have Surrey debutant Theunis de Bruyn - the replacement for Virat Kohli - caught at short cover for a third-ball duck. Leach bowled just four overs while Bess finished with 1 for 27 from 13.
Tom Abell, Somerset's captain, said: "I still think it was the right decision to bowl first and I can't fault the efforts of our bowlers all day.
At times we didn't get the rewards we deserved but we kept going. We beat the bat consistently, a few edges didn't go to ground but they are allowed to play well too."
Burns and Harinath had laid the foundations with an opening stand of 83 in 27 overs. Harinath pulled Josh Davey for six and was on course to celebrate his first Championship appearance of the season with a half-century when he was lbw to Abell, playing across a straight one.
Burns, the leading scorer in Division One this season, continued his prolific form by taking his aggregate to 566 runs in a stand of 75 either side of lunch with Borthwick and it was a surprise when he was misjudged the line and was lbw to Lewis Gregory.
Borthwick's innings was the most fluent of the day. The left-hander drove confidently against the seamers on his way to a run-a-ball 50 and greeted Leach's arrival into the attack just before tea by sweeping his second ball to the boundary.
It took a superb delivery from Tim Groenewald, which nipped back to hit off stump, to remove him for 68 and there was further encouragement for Somerset when they removed de Bruyn, who has been recruited for two Championship games, in the next over.
But Pope was soon in the groove as he became the second Surrey batsman to pass 500 runs this season. His first 24 runs came in boundaries as he put on 50 for the fifth wicket with Patel before Abell picked up his second wicket when Patel drove loosely and was caught behind.
Somerset took the new ball straight away but Pope reached a 60-ball half-century with his tenth boundary and Surrey's fourth bonus point, which they secured in the last over of the day, took them two points above their rivals at the top of the First Division.