Wales sparkled in patches and ran in eight tries, including three for centre Cory Allen, to overpower Uruguay 54-9 in their opening Rugby World Cup Pool A match but the gloss was taken off the victory by yet more injury concerns.
After a dispiriting build-up to the tournament marred by injuries to key players, the Welsh moved level with England at the top of the group on five points ahead of the teams' seismic clash at Twickenham next Saturday.
In the earlier game, a day after Japan's stunning victory over South Africa, normal service resumed in Pool B when favoured Samoa proved too strong for the US in a 25-16 victory.
Samoa had the edge from the start and got the first try when impressive wing Tusi Pisi's grubber kick was touched down by Tim Nanai-Williams, only for an excellent US break to send Chris Wyles over and cut the islanders' lead to 14-8 at the break.
Captain Ofisa Treviranus stretched it with Samoa's second try early in the second half and four penalties by Pisi and another by Michael Stanley ensured that Chris Baumann's barrelling effort for the Americans came too late to make a difference.
Samoa, who have realistic hopes of making the quarter-finals for the first time since 1995, top the pool alongside Japan with four points to the two of South Africa - who they face next in Birmingham on Saturday.
The US play Scotland on Sunday.
Meanwhile, France suffered a major setback to their campaign when winger Yoann Huget was ruled out with a knee injury.
Huget sustained an injury to his right knee ligaments in his team's Pool D opener, a 32-10 win over Italy on Saturday, coach Philippe Saint-Andre explained.
"It is sad to lose such a player. We don't know yet whether his ligament is totally or partially ruptured, but his World Cup is over," he told reporters.