Last player to score 4 tries before Ashton in a Five/Six Nations game - Rory Underwood (vs Fiji) and Josh Lewsey (vs Uruguay) scored 5 in a game between those two.
Chris Oti (vs Romania), Neil Back (vs Netherlands), Jerry Guscott x2 (vs Netherlands - same game as Back, and vs USA) and our very own Nick Easter (vs Wales - World Cup warm up) all scored 4 in a game in that period.
If we are pulling out names from the deep past, then Ronald Poulton would get into the centres.
England Captain of his time and the last player before Chris Ashton to score 4 tries in a game for England.
http://www.espn.co.uk/rugby/story/_/id/12823257/the-remarkable-story-ronald-poulton-palmer