Smith claimed a season's best 6 for 32 and Walsh returned 4 for 50 as the visitors were skittled out for 95 in their second innings. The openers Bobby Dawson and Tim Hancock promptly rattled off the nine runs required for Gloucestershire's ninth County Championship win of the season. Victory maintains their interest in the title race - but Northamptonshire appear doomed to finish in the bottom three.
Smith and Walsh again showed the qualities which have brought them 147 first-class wickets this season, the most productive new ball pairing in county cricket. But there was a lack of application evident about the visitors' batting, epitomised by the dismissal of their captain, Kevin Curran.
Curran had seen David Sales depart in the opening over after lunch but, two deliveries later, he still attempted an expansive drive at Walsh, which only resulted in a skied catch to Dawson at mid-on.
The score had reached 83 for 7 when light rain halted play early in the afternoon. It was three and a half hours later before play was able to resume, but Smith and Walsh wasted no time in wrapping up the innings.
Only one session was possible at Southampton between Hampshire and Middlesex due to rain.
Hampshire were all out for 311 after resuming at 291 for 9 and in their second innings Middlesex were 105 for 2 with Mike Gatting unbeaten on 33.
The pace man Richard Johnson was the most successful of the Middlesex bowlers, taking 4 for 75.
Gavin Haynes was Worcestershire's main man on a rain-ruined day at Taunton, taking three of the morning's five wickets to earn figures of 4 for 38 from 16 overs as Somerset slumped from 33 for 1 to 135 for 6 at lunch, responding to the visitors' modest 244.Reuse content