The Sydney Thunder would not have qualified for any Big Bash League finals series before this one. Having benefited from the addition of a fifth team, they are now a game from playing off for the trophy against the Sydney Sixers after edging past the Adelaide Strikers in a nervy-wracked affair at Adelaide Oval.

All three BBL finals so far have been won by the team batting first, and once again the pressure of the situation got to the Strikers just as they appeared set to run down the Thunder's 7 for 151. From 3 for 115 needing 37 from 31 balls, the Strikers lost 6 for 24 to ultimately fall nine runs short of winning through to face the Melbourne Stars at the MCG on Thursday night.

The tale of the game was ultimately told in how the Thunder captain Callum Ferguson was able to rely upon three outstanding spells from Jono Cook, Daniel Sams and Chris Morris, whereas the Strikers' otherwise excellent bowling display had been let down by Billy Stanlake and Wes Agar leaking 75 off seven overs between them.

Heavy rain in Adelaide had provoked doubt over whether the match would begin on time or even be completed at all, but the skies cleared and the ground drained with more than enough time to spare. The weather left in its wake a fresher pitch than usual for an Adelaide Oval T20 match, convincing the Strikers captain Travis Head to send the Thunder in, having batted fist whenever possible in earlier home matches.

The strategy for the Strikers, then, would have appeared obvious, in terms of bowling a little fuller than usual to seek movement and outside edges. However, Stanlake and Agar appeared not to have got the memo, dropping down obligingly short for Usman Khawaja briefly and then Alex Hales at length to use their power off the back foot. Siddle and Michael Neser were far more intelligent in their approaches, often beating the bat whenever they bowled a driveable length, meaning the Thunder scorecard soon developed a lopsided appearance.

So while Hales scored freely, others struggled, though Ferguson was very unfortunate to be fired out lbw to Siddle by the umpire Paul Wilson - the ball looked to be comfortably clearing the stumps as the batsman tried to pull it. Hales' innings was ended when he misread a Rashid Khan leg break as a wrong'un and edged it tamely to point, and the sight of Arjun Nair walking out to bat at No. 5 did not say much for the Thunder's batting depth.

Consequently, the innings gradually decelerated, as 2 for 89 after 11 overs deteriorated to 7 for 151 after 20. While Stanlake and Agar went for 75 between them from seven overs the e other Strikers bowlers cost just 76 from the remaining 13, and only Morris could pass 20 from among the Thunder's middle-order players.

There was some excellent bowling upfront by the Thunder to give themselves a chance of defending their mediocre tally. Sams flummoxed Phil Salt with a slower ball to draw a catch to mid-on, Jake Weatherald was hurried out by an excellent bouncer from Chris Tremain, and Head, after looking composed and proactive, contrived to drag Cook's wrist spin onto the stumps to have the Strikers uncertainly placed at 3 for 65 in the 10th over.

But the depth of the Strikers' batting line-up was underlined by the fact they had Jon Wells - the leading middle-order batsman in the tournament - coming in at No. 5 whereas the Thunder had needed to send in Nair. What followed was a 50-run stand in 35 balls between Wells and Alex Carey, as the target was quickly whittled down through deft placement and strategically timed boundaries. It was a surprise, in fact, when Carey was run out by a direct hit from Ferguson, leaving Wells with the primary responsibility.

He could only watch at the non-striker's end as Rashid slogged Cook into the outfield to leave him with another fine set of figures, and Matt Short was then pinned lbw by a Morris delivery that was swift and straight. Wells and Neser then allowed the equation to drift out to 34 required from the final three overs, before they sized up Tremain. Neser's obvious intention to walk towards the off side had Tremain bowling wide, and four times in the 18th over he pitched on our outside the tram lines to hand the Strikers a run.

Two more boundaries meant the over cost 16 all up, and though Neser and Siddle departed in the penultimate over, Wells was left on strike needing 13 from the 20th. Given his tournament, Wells could reasonably have been expected to do the trick, but he edged an eminently cuttable Morris delivery first ball to depart, and more or less decide the game. The Thunder had, remarkably, required the bottom Melbourne Renegades to beat the Brisbane Heat to reach the finals at all, and now they are a game from a competition decider against their crosstown rivals.