Coral did the same offer tonight - put on a £10 correct score and get a free £10 in play. Put 2-0 on and was going to stuck 3-0 on when the match started, but luckily they didn't credit it properly so I couldn't use it until half time. So instead I put it on a headed goal in the second half at 4.33.
Amazing match, can't really believe it's actually happened. Searching through my post history to see if I've mentioned supporting Wales before so I don't look like a glory hunter.
If a return is unexpectedly high, that means you should check your bet, not place it ASAP. If it's any consolation, Williams scored in the 30th minute.