Fifth seed Clayton won the opening leg against Rob Cross but did not have another dart at a double, losing 5-1 in around 10 minutes as the former world champion averaged 114 and hit 83 per cent of his doubles.
Cross took out 138 and 137 in a run of five straight legs and plays Anton Ostlund in Monday's Group G decider.
Rock, the eighth seed, had to beat Kevin Doets and drop no more than two legs after losing to Tommy Morris on Saturday, but was beaten 5-3. Doets averaged 100 and hit five 180s, and meets Morris on Monday night to decide Group C.
Woodhouse, seeded 15th, lost five legs in a row in a 5-1 defeat to Krzysztof Ratajski, who faces Tom Sykes on Tuesday for top spot in Group J.
Cameron Menzies came from 3-1 down to beat Raymond Smith 5-4 in Group D, levelling the match with a 162 checkout in the sixth leg, and plays Stephen Bunting on Monday to decide the group. Smith goes out having lost both of his matches in a deciding leg.
Andrew Gilding averaged 81 but still beat Charlie Manby 5-4 in Group F, finishing with a 124 checkout on the bullseye. Manby missed his first 12 darts at a double and recovered to lead 3-2 before Gilding won three of the last four legs to set up a meeting with Ryan Searle on Monday.
Niko Springer beat Adam Sevada 5-1 in Group H despite hitting two Robin Hoods and will reach the last 16 if he beats Wessel Nijman on Monday. Alan Soutar's 5-2 win over Lisa Ashton means the winner of his match with Jermaine Wattimena on Monday goes through from Group B.
Maik Kuivenhoven recovered from 4-1 down to beat Karel Sedlacek 5-4 in Group P but was still eliminated, and Sedlacek needs a big win over Nathan Aspinall on Tuesday to qualify.
Ross Smith is among those in action in the evening session, the two-time major winner needing to beat Gabriel Clemens to stay in the tournament after his opening defeat to Rusty-Jake Rodriguez. Beau Greaves is in the same position against Niels Zonneveld following her 5-2 loss to Luke Littler on Saturday.
Joe Cullen, Martin Schindler and Ricky Evans all play their first matches, while Henry Coates faces Jeffrey de Graaf after missing two match darts against Michael van Gerwen on his debut.