Khan's heroics have helped lift Adelaide to the top of the ladder, though they only lead on net run rate from the Renegades, Heat and Scorchers. But now after nearly half way passed in the season, Adelaide Strikers is in top position on the BBL point table where Sydney Thunder is in 5th position.
The Afghani import took two wickets for the fifth straight game to underline his status as one of the most influential imports in this season's tournament.
Rashid Khan, the 19-year-old who looks 29, smacked 16 runs off six balls, including two giants sixes in the final over.
Buttler, who is second in the Thunder run aggregates with 202 at 33, will be replaced by compatriot James Vince. But Sydney Thunder could not chase the score but finished their innings by scoring 133 runs.
Also returning to the Thunder fold is Test batsman Usman Khawaja, who will be coming off a big hundred in the final Ashes match.
He has averaged 32.60 in five T20 internationals and last summer scored 74 runs at 24.66 in three BBL games for Thunder.
"That wasn't great, and in the scheme of the game it worked against us, " Watson said of Ingram's double life. So, Adelaide Strikers won by 25 runs.
"We're not far away, it's not like we're playing bad cricket", Watson said. Khan posted 2-21.
Veteran Ben Rohrer (29 off 13) clobbered 23 off the 18th over, bowled by Ben Laughlin, but it wasn't enough against a disciplined Strikers attack. Openers added 45 runs to the scoreboard when Buttler was gone with 21 runs.
Once Kurtis Patterson (29 from 36 balls) and Watson (14 from 16) departed, the night was as good as over for the men in lime.
After hitting six fours and a six in their powerplay overs, the Thunder could muster just two boundaries in the next ten prior to Rohrer's late cameo.
Coming off a rapid-fire 66 in his last game, Ingram belted four sixes and two fours for the Strikers.
South Africa's Colin Ingram gave the Strikers some much-needed momentum at the back end of their innings, hammering four sixes in his knock of 48 from 31 balls.
Chris Green deserved better than 1-22 after giving up just seven runs in his first three overs, while ever-reliable tweaker Fawad Ahmed really enjoyed his 3-31.