Lanning and McGrath powered Australia to the highest total of the series so far before Alana King took 2-11 from three overs to continue her excellent tour.
Ireland enjoyed a fine start with the ball, limiting Australia to a score of 39-2 after six overs. Georgina Dempsey was the first bowler to strike, ending the second over of the innings by trapping Alyssa Healy lbw for 1.
While Lanning immediately looked at home out in the middle, Australia were dealt another blow when Rachel Delaney struck in her first over; Beth Mooney failed to get the right connection off a full toss, finding Arlene Kelly at mid-on to depart for 9.
That brought Lanning together with McGrath and after a quiet couple of overs, a pair of sixes from Lanning off Kelly’s second over got Australia moving.
Regular boundaries followed as Lanning and McGrath targeted all corners of the ground; the former brought up her half-century off 31 balls while the latter took 30.
Together their partnership was worth 135, the highest third-wicket stand for Australia Women in T20Is.
Lanning finally departed for 74 in the penultimate over of the innings, when Dempsey took an excellent catch at deep square leg off the bowling of Kelly.
T-Mac wins Player of the Match AGAIN!
Her T20I career to date:
42* (33) v India – POTM ✅
44* (31) v India – POTM ✅
91* (49) v England – POTM ✅
70 (45) v Ireland – POTM ✅
That’s an average of 247, a strike rate of 156 and a 100% Player of the Match record! pic.twitter.com/YmzvQW03Iy
— cricket.com.au (@cricketcomau) July 21, 2022
Teenager Dempsey was in the action once again in the final over, removing McGrath for 70 as she finished with figures of 2-35 from her four overs. There were economical displays from Leah Paul (0-20 off three overs) and Ava Canning (0-18 off her three) but Australia’s total of 182-4 was an imposing one.
The Australians made inroads with the ball quickly, with Rebecca Stokell departing for 1 in the first over of the reply to Megan Schutt.
Fellow opener Gaby Lewis found Lanning’s safe hands off the bowling of Jess Jonassen in the fourth over but Orla Prendergast looked in fine touch, hitting four boundaries to move to 20 off just 13 balls.
A healthy partnership was brewing between skipper Laura Delany and Prendergast, but their stand of 36 was broken by leg-spinner King. In her first over, King lured Prendergast down the ground only for the ball to sneak through the advance and strike the stumps.
King struck once again in her next over, turning the ball past Rachel Delaney to have the right-hander stumped for 3.
Australia’s bowlers tied down run-scoring in the middle overs and regular wickets meant Ireland were unable to pose a significant threat as the innings wound down.
Prendergast finished as Ireland’s top-scorer with 25, while King, Jonassen and Schutt picked up two wickets apiece.
Ireland v Australia, 4th Tri-Series T20I, Bready, 21 July 2022
Australia 182-4 (20 overs; M Lanning 74, T McGrath 70; G Dempsey 2-35)
Ireland 119-7 (20 overs; O Prendergast 25, L Delany 21; A King 2-11)
Australia won by 63 runs