"We will fancy chasing any target Surrey can set."

That was the message from Somerset centurion Lewis Gregory at the end of an intriguing day of Specsavers County Championship cricket in Taunton, which saw Surrey lead by 134 runs thanks to a second innings which stands at 152-5.

Gregory was the star man for the hosts with an unbeaten 129 - his second First-Class century - as Somerset posted 398, for a first innings lead of 18 runs.

Having resumed on 243-5, a deficit of 137 runs, Day 3 of the match began badly for Somerset as Steve Davies (58) could only add four runs before falling to pantomime villain Gareth Batty.

Yet all-rounder Gregory moved to his half-century in confident fashion, and with the support of Craig Overton and Tim Groenewald at the other end he cut loose to bring up his ton (off 121 balls).

Disappointingly for the home side, they fell two runs short of a fifth batting point when Jack Brooks - nursing a calf injury - was clean bowled by Rikki Clarke.

Gregory had ended unbeaten on 129 (from 153 balls, with 10 fours and five sixes), and he showed his ability with the ball by helping reduce Surrey to 19-2 at the start of their second innings.

Mark Stoneman edged Gregory to Marcus Trescothick at slip, and then Scott Borthwick was trapped lbw by Overton.

With ex-Somerset man Dean Elgar unable to bat due to illness (kidney stones), Surrey lost Ryan Patel to Jack Leach, and when Gregory removed Ben Foakes it was 94-4.

Visiting skipper Rory Burns resisted for a while, though, reaching his second 50 of the match before being stumped by Davies off Leach.

Morne Morkel and Will Jacks negotiated the final two overs of the day, for a lead of 134 runs without further loss, but Somerset will be hopeful of forcing a result on the fourth and final day tomorrow.

Afterwards, star man Gregory said: "You experience plenty of tough days in cricket, so it's important to enjoy the good ones like I had today.

"I had no fixed plan at the start, just to watch every ball as closely as possible.

"I had a lot of help from my team-mates.

"Tim Groenewald played a particularly brave innings, although I have to admit laughing at the other end when he kept getting hit.

"Taking two wickets in the Surrey second innings made it an even better day for me.

"It's still a good pitch and we will fancy chasing any target Surrey can set."