Malan had registered single-figure scores in the back-to-back wins at Cardiff, with just one 50 in his last seven innings, but the world No 1-ranked T20 batsman sparkled in a knock containing five fours and four sixes after being promoted to open the batting.
Malan has also been linked with a Test recall after a fine 199 for Yorkshire in his most recent County Championship match, with a number of England batsmen’s positions under scrutiny after the series defeat to New Zealand.
The 33-year-old has not played in the format since August 2018 but did register an Ashes hundred – his only Test century – on the last trip to Australia in 2017-18.
While England are set to head Down Under later this year as they look to regain the urn, Malan insisted adding to his 15 Test caps has not been on his mind.
He said: “It’s not something I’ve been thinking about. If I got that call, I’d love to play Test cricket again for England. If it is in Australia with a Kookaburra ball that does slightly less, I’d take that as well.
“But I’d always want to play all three formats of cricket for my country, whether I’m good enough or not is a different story.”
On Saturday, Jason Roy’s tight hamstring led to a batting reshuffle and Malan and Jonny Bairstow, who made 51 off 43 deliveries, put on 105 in 11.4 overs, before Dushmantha Chameera’s career-best 4-17 restricted England to 18-6.
It was a masterclass in death bowling from Chameera as he varied his pace and lengths to bamboozle several England batsmen in a mini-collapse, but the hosts already had enough runs as Sri Lanka’s batting was once again sub-par.
In what has been a recurrent theme of the series, Sri Lanka lacked scoring options and England were collectively excellent with the ball, David Willey taking 3-27 while fellow left-armer Sam Curran collected two wickets.
Sri Lanka ultimately capitulated to 91 all out in 18.5 overs as they lost the series 3-0, having started the day by winning the toss for the third time, on this occasion handing over to Bairstow and Malan after electing to field.
Malan was shoulder-barged to the floor by Binura Fernando while attempting a quick single and while there were no cross words between the pair, the England batsman clipped the left-arm seamer off his toes for the first maximum.
Isuru Udana had a forgettable introduction, sending down four wides in a 10-ball over as England racked up 48 in the powerplay, with Bairstow mixing some agricultural strokes with more authoritative drives.
Bairstow farmed the strike for much of his stand with his fellow Yorkshire batsman, but it was Malan who showed more aggression, upping the ante off Wanindu Hasaranga with a reverse sweep that beat two diving fielders and an exquisite drive over cover for fours, either side of heaving a sweep for six.
Bairstow went to a 41-ball 50 before playing around Udana’s yorker to be bowled as Sri Lanka made a belated breakthrough in the 12th over, but Malan reached his half-century from just 30 deliveries, his 12th 50-plus score in just 27 T20 innings.
Malan then belted Hasaranga for two towering leg-side sixes in a 15th over that yielded 18 runs, but from a position of 143-1, England lost five wickets in 23 legal balls as thoughts of a 200-plus total vanished.
A 181 target was always likely to be daunting for a side that had made 129 and 111 at Sophia Gardens, where they found boundaries hard to come by. While Danushka Gunathilaka caressed the first ball of the reply through cover for four, Willey had his revenge immediately afterwards when an edge was pouched by Malan at second slip.
Chris Woakes, in for the rested Mark Wood, had his first T20 international wicket since November 2015 when Kusal Perera’s leading edge was taken by Liam Livingstone, running in from deep midwicket to take a low, diving catch, while Sri Lanka lurched to 29 for three in the fifth over when Kusal Mendis tentatively nicked off to Willey.
From the preceding ball, Mendis had deposited Willey over the rope, while Oshada Fernando did likewise to Jordan but it was a frenetic stay from Sri Lanka’s No 3, who was eventually put out of his misery for 19 from 27 balls when a leading edge off Sam Curran looped to gully.
Dasun Shanaka was ran out following a smart pick up and flat throw from Billings at long-on, with the writing on the wall in the afternoon sunshine by this stage.
They avoided setting a new benchmark for the lowest T20 score in their history – which remains 82 against India in February 2016 – but any hope of a surprise victory had long since vanished.