Two late goals from Martin Petrov and Johan Elmander helped Wanderers register their first victory of pre-season on British soil in a 2-0 win at McDiarmid Park.
It was to be a happy return to his old stamping ground for Owen Coyle, but again Scottish opponents gave his team a real run for their money.
It was looking likely that a second scoreless draw in three days would be the outcome up until Petrov's brilliant solo goal with a quarter of an hour remaining.
And Elmander's confidence-boosting second strike of pre-season just two minutes later sealed the win.
Successive clean sheets was another obvious plus point for the Whites, while Marcos Alonso also got his first taste of action after coming on as a late substitute.
The first-half was a similar tale to that of the prevous friendly at Falkirk Stadium with the game goalless at half-time.
Owen Coyle started his team in a previously unseen 4-4-1-1 formation with Martin Petrov playing in the hole just behind Kevin Davies. That system was to have a reasonable amount of joy early on as Petrov roamed the field in search of the ball at every opportunity.
The number 10 drifted from flank to flank and was direct with his runs whenever in possession. It was his burst from midfield that brought Wanderers their first shooting chance with ten minutes on the clock.
Just as the Bulgarian was about to pull the trigger he was hacked to the floor, but instead of opting to shoot directly from the resulting free-kick, communication was lost between Matt Taylor, Stuart Holden and Petrov, and the Saints cleared a scrappily taken set-piece.
After Wanderers' spritely start, the hosts started to offer a bit more with a quarter of an hour played.
An attack down the right by Chris Millar forced Gary Cahill into action with the centre-half racing across to intercept ahead of former Swindon Town frontman Sam Parkin.
There were also openings for Marcus Haber, who fired an effort across goal, and a wayward free-kick by full-back Danny Grainger flew harmlessly wide of the target.
On the whole, it was 45 minutes devoid of much goalmouth action as both defences restricted each other's attack to nothing more than half chances.
A clever chipped finish from Kevin Davies almost brought the skipper his first goal since the second pre-season friendly against Charleston Battery.
And shortly before the break Parkin opted for a similar lofted finish from 18 yards to which Jaaskelainen was on his guard, saving with relative ease.
Bolton started the second-half in the ascendancy, creating two openings within five minutes of the restart.
Goalkeeper Graeme Smith thwarted Chung-Yong after the South Korean had ghosted in unmarked and referee William Collum somehow failed to spot Steven Anderson's shirt pull on Petrov with the attacker having left the Saints' defence in his wake with a lung-bursting dart into the box.
Bolton had controlled the second-half without asserting themselves too much, however they were extremely lucky not to find themselves going a goal behind on 65 minutes.
Chris Millar had timed his run to perfection but when faced with the on-rushing Jaaskelainen, he was caught in two minds and opted to play his pass in between substitute Scott Dobie and the far post instead of taking the selfish option and shooting.
The Scottish side had another decent opportunity to go a long way towards claiming an English Premier League scalp when Dobie headed wide of the post when he really should have at least worked Jaaskelainen.
And they were to regret missing those two chances as Petrov and susbstitute Elmander struck a quick-fire double to seal the victory for Wanderers as the game entered its latter stages..
Moments after Marcos Alonso was given his first taste of action in the white shirt of Bolton, Petrov collected a long, cross field pass from Robbie Blake before taking the ball in his stride, cutting back onto his left foot and drilling past Smith at his near post.
Elmander's strike was not too dissimilar as again space on the right wing was exploited. The Swedish striker took his time before slotting across goal and into the far corner of the net.
Gretar Steinsson came within a couple of yards of making it three in the final minute with a curling effort from the edge of the box, but a 2-0 winning margin was a satisfying way to end the mini-tour of Scotland.
St Johnstone: Smith, Trialist, Grainger, Morris, Anderson, Millar, Davidson, Parkin (Dobie 60), Craig, Haber (Samuel 46) (Subs: Caddis, Rutkiewicz, Gartland, May, Taylor, Dobie, Jackson, Duffy)
Wanderers: Jaaskelainen, Steinsson, Cahill, Knight, Robinson, Chung-Yong (Marcos Alonso 74), Holden (Mark Davies 70), Muamba, Taylor (Blake 64), Petrov, Kevin Davies (Elmander 74) (Subs: Bogdan, Ricketts, Andy O'Brien, Samuel, Basham, Alonso, Joey O'Brien, Gardner, Davis, Cohen, Riga, Elmander)
