Swindon hit Walsall with three quick-fire goals in the second half to seal a 4-1 victory at the Banks's Stadium.It was a result that never looked likely as a highly competitive first half ended 1-1, but defensive errors undermined the home side's efforts and cost them their seven-match unbeaten run.It took Swindon only three minutes to take the lead as Michael Smith turned in a cross from the excellent Massimo Luongo for his 13th goal of the season. But Walsall top-scorer Tom Bradshaw equalised with a low shot from Michael Cain's pass to register his 12th of the campaign after 18 minutes.A minute into the the second half Walsall wasted a corner and allowed Swindon to break quickly, with Luongo driving home a low shot from Nathan Byrne's pass. The, with 51 minutes on the clock, Williams netted from Smith's pass after home defender Paul Downing slipped in the snow.Williams hammered in the fourth for the Robins, and his 14th goal of the season, after a flowing raid and the game ended with players having difficulty finding or seeing their men in the driving snow.