|Bob Willis Trophy final, Lord's (day two)|
|Somerset 301: Byrom 117; C Overton 66; S Cook 5-76, Harmer 2-36|
|Essex: Yet to bat|
Eddie Byrom made a classy century for Somerset before Essex fought back with the new ball on another rain-affected day in the Bob Willis Trophy final.
Byrom compiled just his third first-class ton off 181 balls before falling for 117 in a shortened evening session.
He and Craig Overton (66) shared a sixth-wicket partnership of 127 before Somerset were dismissed for 301.
Essex took their last five wickets for 35 runs with the second new ball as Sam Cook (5-76) claimed a five-wicket haul.
The 2019 county champions will start their reply on the third morning as bad light prevented them from facing three overs before stumps.
The second day had started delicately-poised with Somerset on 119-4.
But Byrom, 23, continued to make the most of his chance in the side at the expense of the injured James Hildreth.
After his battling half-century on the curtailed first day, the Zimbabwe-born left-hander showed more of his classy array of strokes all around the ground.
They included his 15th four to bring up three figures with a crisp straight drive off Cook shortly after lunch.
In doing so, Byrom became the sixth different Somerset batsman to score a century in the competition.
Somerset dominated before lunch, adding 124 runs in the morning session for the loss of just Steven Davies for 27 as Cook had him caught behind by Adam Wheater.
England all-rounder Overton also made the most of a promotion up the order to number seven, reaching a half-century from only 85 balls, which included nine fours in a shade over an hour and a half at the crease.
That helped Somerset reach 255-5 before almost three hours were lost to rain and bad light.
Essex were able to take the new ball shortly after the resumption and it initially brought them three wickets in the space of 19 balls.
Jamie Porter removed Overton lbw with just its fourth delivery before Cook trapped centurion Byrom and then Lewis Gregory in consecutive overs to reduce Somerset to 277-8.
Josh Davey and Jack Leach stood firm to take them past 300 before Leach and last man Jack Brooks were dismissed by Simon Harmer in consecutive balls.
Somerset's first-innings score of 301 could prove decisive should the match finish as a draw - Essex's highest first-innings total in the competition this season is 298.
If the five-day final were to be drawn, the side with a first-innings lead after both have been completed will take the trophy.
Should those two innings not be able to reach their conclusion, the trophy will be shared.
Somerset batsman Eddie Byrom:
"I'm extremely proud to score a century here at Lord's and to do it in a final is extra special. Hopefully it helps set up an amazing win for us as well.
"I was struggling for form a bit before this game so to get back in the runs in this way is really pleasing and it's also my first century in county cricket.
"I've never played here before as well before this game. My last experience of Lord's before this was watching the boys win in the One-Day Cup final last season against Hampshire.
"We know we can bat all the way down to number 11, so we spoke this morning about how crucial building partnerships would be.
"Obviously myself and Craig (Overton) made a valuable one but even at the end, the tail added what could be some vital runs to put us in a great position."
Essex head coach Anthony McGrath:
"It's hard to assess how good a total that is until both sides have batted on the wicket, but the conditions definitely suited bowling more yesterday for sure.
"At 139-5, we were hoping to bowl them out for under 200, but Eddie Byrom and Craig Overton put on a good partnership there and I think we did well in the end to fight back and dismiss them for just over 300.
"Hopefully we can get some partnerships on the board tomorrow and try and chase that down. We know Somerset are a strong bowling line-up, but it looks a decent wicket and we'll be looking to put some pressure back on them.
"I'm really pleased for Sam Cook taking five wickets. He's bowled terrifically lately without necessarily getting the accolades.
"He's got better and better for us and is developing into a really fine bowler."