England 193 for 6 (Moeen 63, Roy 52, Holder 3-44) beat West Indies 159 for 5 (Mayers 40) by 34 runs
Moeen Ali set up a Sunday-night decider in England's series against West Indies at the Kensington Oval, leading from the front as stand-in captain with 63 off 28 balls and two key wickets in the run chase.
With Eoin Morgan ruled out of the series after injuring his quadriceps in the warm-ups on Wednesday, Moeen struck seven sixes - four of them off consecutive balls in Jason Holder's 18th over - as England surged to 193, building on the platform set by Jason Roy's scratchy 52.
West Indies started brightly in pursuit, reaching 56 for 0 after the powerplay with Kyle Mayers making a sprightly 40 on his return to the side, replacing Shai Hope at the top of the order. But England's spinners put the squeeze on: Moeen removed both openers, and Adil Rashid and Liam Livingstone both made breakthroughs on a dry pitch.
Holder and Kieron Pollard kept the run chase alive, but a middle-overs slowdown meant the task was beyond them. The result set up a deciding final match on Sunday night, with the series squared at 2-2.
Roy's late arrival
Asked to bat by Pollard for the third time in the series, England struggled to adapt to the pace of the pitch - the same one used in their one-run win last Sunday night - early on, with Tom Banton plinking a pull to mid-on to give Holder a wicket in his first over. Roy, who was given a life when Holder put down a return catch, looked particularly out of form, creeping to 11 off 19 balls and swearing in frustration over the stump mic after failing to beat the infield yet again.
But 15 balls later he had brought up a half-century, clicking into gear by clubbing Sheldon Cottrell 101 metres over midwicket, and England raced to 80 for 1 after nine overs with James Vince also hitting his straps at No. 3.
Pollard put the brakes on with another canny spell of slow-medium cutters, exchanging words with Roy after angling the ball into his pads to defend the short off-side boundary. He conceded only one run (plus a leg bye) off the seven balls he bowled to Roy, roaring in celebration when Nicholas Pooran gobbled up a thick outside edge from a legcutter.
Moeen cuts loose
When Vince miscued a wide offbreak from Akeal Hosein to short third, England had lost their two set batters in the space of seven balls and the innings threatened to fall away. Moeen and Livingstone traded sixes - Livingstone's, a 91-metre pull over midwicket, was the only boundary Pollard conceded - but a canny 17th over from Cottrell left them 134 for 3 with three overs left.
What followed was a masterclass in death-overs hitting from Moeen. Holder, whose first two overs cost just three runs, leaked 28 off the 18th, including four consecutive sixes from Moeen: a drag over long-on, a dead-straight hit into the press-box window, a languid swing over extra cover and a wristy pick-up over square leg.
Shepherd had Livingstone caught off a steepler with the first ball of the 19th but then suffered some rough treatment himself. Moeen clipped two into the leg side to bring up a 23-ball half-century - his fastest for England - before hitting two more sixes, including a sumptuous chip over extra cover with the full face of the bat.
He miscued Holder to long-on at the start of the final over, and Phil Salt - down at No. 7 - skied his first ball into the covers, but Sam Billings, recalled in place of Harry Brook after missing Wednesday night's game through illness, clubbed the last two balls for six. England added 59 in the last three overs, and Holder's final two cost 41 runs.
Mayers impressed at the top of the order, hitting Moeen for two sixes over the leg side and thumping Tymal Mills' first three balls for four, six and six, but West Indies' chase faded badly against spin in the middle overs. Moeen made the first breakthroughs, having Mayers and Brandon King caught at long-off and long-on respectively, while Rashid maintained the pressure from the other end.
Rovman Powell had played Rashid out during his hundred on Wednesday night, milking him for 11 off 11 balls, but his notorious weakness against wristspin was enough for Billings to bark over the stump mic: "Still love this match-up!" Three balls later, he ripped a googly through the gate which crashed into middle-and-off stump.
56 for 0 after the powerplay became 84 for 3 off 13, and after Pooran hit Livingstone for consecutive sixes, he holed out to long-on looking for three in a row. Holder's 36 off 24 - his highest T20I score - kept West Indies' hopes alive, but Reece Topley and Chris Jordan kept their composure to close things out at the death.