Crawley Town manager Francis Vines locked his team in their dressing room for almost an hour after the league leaders crashed to defeat away to Merthyr Tydfil.

A goal in each half handed Merthyr victory in a hard-fought match at Penydarren Park.

"We are unhappy with the performance but don't want to lay into the lads too much," said assistant manager Dave Swindlehurst.

"We have games coming up thick and fast and we've toned down what we said. The boys have been doing well but we didn't adapt to the way Merthyr played. They sat back and hit us on the break."

There was some good news for Crawley on the night when they heard that title rivals Weymouth had lost 4-3 at Nuneaton.

"We heard Weymouth were 2-0 down at half time and told the players in the hope that it would gee them up, but that clearly didn't work," said Swindlehurst.

Crawley arrived with hopes of extending their lead at the top of the premier division table to six points.

They almost took the lead in the first half when Charlie MacDonald saw his glancing header saved superbly by the keeper.

Merthyr struck the first blow immediately before half time when Cortez Belle headed in at the near post from a Danny Carter corner.

Belle, 20, has now scored 17 goals this season and enhanced his reputation as a raw but talented striker. He is attracting strong interest from Cardiff.

The Martyrs went 2-0 ahead on the hour when Danny Keddle headed in a Kevin Evans' free kick. MacDonald pulled a goal back from a penalty after 74 minutes.

Crawley included midfielder Robert Kember who has signed from Ryman premier division club Basingstoke Town.

Kember, 22, is the son of former Crystal Palace manager Steve.