Leg-spinner Zampa claimed four wickets as Australia bowled out Sri Lanka for 209 despite half-centuries by Kusal Perera (78) and Pathum Nissanka (61).
Adam Zampa, Josh Inglis and Mitchell Marsh delivered when their team needed them the most as Australia breathed life into their floundering World Cup campaign with a five-wicket win over Sri Lanka in Lucknow on Monday. (Scorecard | Highlights | Full Coverage)
Leg-spinner Zampa claimed four wickets as Australia bowled out Sri Lanka for 209 despite half-centuries by Kusal Perera (78) and Pathum Nissanka (61).
Looking on course for a 300-plus score, Sri Lanka faced a bizarre batting collapse to lose 10 wickets for 84 runs.
Inglis (58), who scored his maiden World Cup fifty, Marsh (52) and Marnus Labuschagne (40) then did the heavy lifting with the bat as Australia overhauled the target in 35.2 overs, giving a solid boost to their net run rate.
While Australia rose to eighth position on the table with their first win of the tournament, the loss severely dented Sri Lanka's chances of progressing to the semifinals as they sit at the ninth spot with three defeats from as many games.
Defending a below-par total, Dilshan Madushanka (3/38) bowled a fiery first spell which included a maiden over and a double wicket maiden in which he claimed the prized scalps of David Warner and Steve Smith.
Warner immediately called for review when the field umpire gave him out. The prolific southpaw left the ground fuming when the DRS ruled it in favour of the on-field umpire. Smith on the other hand was caught plumb in front of the wicket.
While Madushanka was frugal, Marsh took off against the other bowlers. He smashed three boundaries to plunder 12 runs off young spinner Dunith Wellalage in the ninth over.
Marsh raced to his fifty but Chamika Karunaratne sent a sharp throw from the deep to end his innings, as wicketkeeper Kushal Mendis made no error in collecting the ball and disturbing the stumps.
Inglis, playing only his second World Cup game, looked confident in the middle and stitched a 77-run partnership with Labuschagne as Australia crossed the 200-run mark for the first time in this edition of the World Cup.
Earlier, an out-of-form Perera got some much-needed runs while Nissanka struck his second consecutive fifty.
Australia benefitted from the timely return to the form of Zampa, who had been having an awful tournament. The wrist-spinner enjoyed an excellent outing to help bundle out Sri Lanka in 43.3 overs.
Lots were going on in the field as Mitchell Starc aborted his delivery stride thrice to warn Perera to not leave his crease early on at the non-striker's end.
Perera was also struck in the head by a Marcus Stoinis bouncer which caught the Sri Lankan off guard.
But the experienced southpaw didn't let the blow deter him and went on to send Stonis' slower cutter down the ground to bring up his fifty.
With both openers pilling on the runs, the Australian bowlers looked clueless. But skipper Pat Cummins kept shuffling his bowlers in search of that first breakthrough.
Cummins, who has been far from his best with the ball, stood up at the opportune moment to give Australia the breakthrough they needed.
Cummins cramped Nissanka for room and the Sri Lankan hit it high and in front of the square only for Warner to run and complete a stunning catch.
The Australian skipper bowled a peach of a delivery five overs later to clean up the other set batter in Perera, who picked the wrong line to swing his bat.
The dismissal marked the beginning of Australia's dominance as the Sri Lanka batting unravelled and the five-time champions grew in confidence.
Zampa (4/47) got rid of the in-form Kusal Mendis. But the wicket belonged to Warner who ran across from deep midwicket, covering about 25ms to complete a spectacular diving catch.
Sadeera Samarawickrama, Chamika Karunaratne and Maheesh Theekshana were Zampa's other victims with Starc pitching in with two wickets.
Apart from the openers and Charith Asalanka's 25, no other Sri Lankan batter reached double digits.