An astonishing decision by captain David Byas robbed Yorkshire of the opportunity to seal victory over Glamorgan at Swansea yesterday.

Yorkshire blasted out Glamorgan for only 104 soon after lunch and with a first innings lead of 176 and his bowlers still fresh it seemed Byas would enforce a follow-on.

But he declined and with bad weather forecast he has opened up the possibility of Glamorgan getting out of jail with a draw.

Byas then hit an unbeaten 64 to hurry Yorkshire on to 208 for six by the close when their lead was an almost unassailable 384

"I was unsure what to do but I did not want to face the prospect of Glamorgan drawing level and possibly going ahead by close of play so I decided the best thing was to bat them out of the game," explained Byas.

His plan could still backfire on him but if the weather stays dry then Yorkshire should have no difficulty in converting their mastery into a win which would give them an even bigger lead at the top of Division One of the CricInfo Championship.

Glamorgan had no answer to Chris Silverwood who snatched five for 20 runs and must have been looking forward to ripping through the batting again. It was blistering form which suggests a Test recall may be close. Silverwood grabbed three at no cost and after lunch he failed by a whisker to achieve a hat-trick as Glamorgan caved in. Gavin Hamilton and Ryan Sidebottom picked up a couple each.

Byas's decision looked even harder to justify as Yorkshire plunged to seven for two with openers failing again, Matthew Wood becoming Bradford-born Alex Wharf's 100th victim in first class cricket and Scott Richardson also falling.

Craig White and Darren Lehmann added 46 before being out. Byas and Fellows avoided further embarrassment with a stand of 120 in 30 overs.

Fellows lofted him for two sixes in his 77-ball 50 which also contained five fours and Byas included on one-driven six in his second 50 of the game, the first time a Yorkshire batsman has done this in two seasons.

The partnership ended when Fellows, on 61, tickled Wharf down the legside for Shaw to take his third catch. Blakey was soon out but Hamilton kept Byas company until the close when Glamorgan needed no reminding that their biggest winning score at Swansea stands at 311.