(Updates after Hull City-Sunderland) * Third-tier United beat Charlton 2-0 * Hull reach last four with win over Sunderland * Manchester City v Wigan later on Sunday LONDON, March 9 (Reuters) - English third-tier club Sheffield United kept alive their FA Cup dream on Sunday when two goals in as many minutes gave them a 2-0 victory over Charlton Athletic and a place in the semi-finals. They were joined in the last four by Hull City, who overcame a missed penalty by Sone Aluko to trounce Sunderland 3-0 in their all-Premier League quarter-final at the KC Stadium. More...