Magpies head coach Craig Philpott was thrilled with how well his team's set piece play worked. He was particularly impressed with the three tries off lineout plays.
Philpott agreed the Magpies' ball retention and patience was the best it had been all season.
He will give his troops the weekend off and preparation for the September 24 match against the Tasman Makos at Napier's McLean Park will begin on Monday.
"It's been a big 19 days with five games," Philpott added.
Along with West, second five-eighth Tiaan Falcon and Emerson impressed in the Magpies backline. Lock Geoff Cridge had his best game of the season with accurate lineout play and powerful carries.
The Stags opened the scoring in the third minute with a penalty to first five-eighth Wharenui Hawera from 57 metres out.
The hosts' defence was solid until Magpies halfback Brad Weber returned from a visit to the head bin and scored in the 12th minute off a set play from a lineout, which also involved lock Mark Abbott and flanker Tony Lamborn.
West, who had earlier missed a penalty attempt, added the conversion. Southland closed the gap through another Hawera penalty in the 21st minute.
Hawera was again on target with a penalty in the 35th minute from 34m out. Three minutes later West put the Magpies back in front with a handy penalty when Bay of Plenty referee Glen Jackson pinged the Stags for not being 10 metres and the villain, No8 Mika Mafi, was sinbinned.
Just before the halftime whistle, Hawera gave the Stags a 12-10 lead when West was sinbinned for a holding back infringement 40m out from the Magpies' posts.
The Magpies made a superb start to the second half with two quick tries during the first four minutes of the second half to captain and hooker Ash Dixon and fullback Matt Garland. Falcon converted Garland's, which came off a clever offload from wing Jonah Lowe.
However the Stags refused to throw in the towel. Another Hawera penalty in the 49th minute kept them in touch.
A 58th minute try to substitute prop, Fiji international Peni Ravai, which Hawera converted, had the game tied up at 22-all.
That piece of class from West and Emerson, a converted try scored by Lamborn and then West's converted try had the Magpies up 43-22 with eight minutes remaining.
Stags wing Tauasosi Tuimavave kept the hosts' hopes of a bonus point alive with a converted try. But when West secured loose ball before the final whistle those hopes were dashed.
Hawke's Bay 43 (Brad Weber, Ash Dixon, Matt Garland, Mason Emerson, Tony Lamborn, Ihaia West tries; West pen; West 4, Tiaan Falcon cons ) Southland 29 (Peni Ravai, Tauasosi tries; Wharenui Hawera 5 pens; Hawera, Tuimavave cons). HT: Stags 12-10.
Match highlights:
Heartstopper: The sinbinning of Magpies pivot Ihaia West for a holding back infringement just before halftime. Fortunately it didn't impact on the game's outcome..
Turning point: West's 72nd minute try which he converted to give the Magpies a 43-22 lead. The Stags were still in the hunt until then.
Player of the match: West. Although he was sinbinned it was still a memorable 50th.
