After a disappointing first half of the season on their return to the Championship, Blues have been moving in the right direction in 2026, helped by six January arrivals demonstrating their undoubted ambition.
The heavy midweek loss at Millwall was a first in nine games, but they have maintained strong home form to keep them in the hunt for a play-off spot as they chase successive promotions.
To do that now, they will require an almost faultless final third of the campaign.
Tommy Doyle brought a fine save out of Sol Brynn inside the first three minutes before they were rocked by Targett's two goals.
Ducksch halved the deficit following a fine cutback from Jay Stansfield three minutes into the second period and the Germany forward almost equalised but Brynn got down low to push his effort behind.
Blues looked much improved from the passive outfit they had been in the first half.
However, just as they were trying to build up a head of steam, Boro's third finished off their chances.
Slovakia forward Strelec was about to be substituted, but stayed on long enough to score a textbook header from Ayling's cross for his first goal since mid-December, and a crucial one in Boro's quest for promotion.
With Ipswich Town in fourth and fifth-placed Hull City meeting on Tuesday, the gap between themselves and the chasing pack could be reduced to three points, emphasising just how much the Teessiders needed this result.