Scotland pulled off a shock six-run victory over Bangladesh at the Twenty20 World Cup on Sunday thanks to a man-of-the-match performance from a former Amazon delivery driver as Oman handed debutants Papua New Guinea a 10-wicket rout.
In the unlikely surroundings of a 3,000-seat stadium on the outskirts of Muscat, after the global showpiece was chased out of India by Covid-19, Scotland recovered from 53-6 to stun the Tigers, ranked six in the world.
Greaves, 31, and playing just his second T20 international, sent back Shakib Al Hasan (20) and Mushfiqur Rahim (38) to dent Bangladesh's chase.
Pace bowler Brad Wheal returned figures of 3-24 as Bangladesh suffered an early setback in their fight to make the Super 12 stage.
"Really proud of Greaves, he had to sacrifice a lot. He was delivering parcels for Amazon not long ago and now he's getting man of the match and playing against Bangladesh," said Scotland skipper Kyle Coetzer.
Scotland are second in the early Group B table, just behind Oman. The top two teams will advance into the next stage and join the heavyweights in the seventh edition of the T20 World Cup.
Greaves, who does not have a central contract with Cricket Scotland, said he was delighted with his all-round display.
"It was just to rebuild the innings at that stage and see where we could go from there. I was happy to be that person. With the score on the board, you've got something to bowl at."
The only bright spot for Bangladesh was Shakib taking two wickets which allowed him to surpass Sri Lanka's Lasith Malinga as the leading wicket-taker in T20 internationals.
The 34-year-old all-rounder now has 108 wickets in 89 matches since his debut in 2006.
"Bowlers did their job really well but the batting unit wasn't good enough," said Bangladesh captain Mahmudullah Riyad.
Earlier, Oman skipper Zeeshan Maqsood returned figures of 4-20, which included three in one over, as tournament debutants PNG struggled to 129 for nine.
Openers Aqib Ilyas (50 from 43 balls) and Jatinder Singh (73 from 42) then clattered the PNG bowlers around the ground without being parted to steer Oman home with 6.2 overs to spare.
PNG captain Assad Vala, who made 56 off 43 balls, and Charles Amini, who smashed 37, had briefly given their team hope with an attacking third-wicket partnership of 81.
"They were batting very well when I got the wickets. And because we got the wickets, they couldn't put on a big total," said Maqsood.
Maqsood sent back Norman Vanua, Sese Bau and Kiplin Doriga in the space of five deliveries and later took one more as PNG, who had been 0-2 at one stage, collapsed from 102-3.
"It wasn't a good start with the bat, losing two wickets with no runs," said Vala.
Ireland, Namibia, Netherlands and 2014 champions Sri Lanka join the qualifying fray on Monday.
The eight teams in the first round of qualifying are chasing four places in the Super 12 round-robin stage.
England, Australia, South Africa, defending champions West Indies, India, Pakistan, New Zealand and Afghanistan will be waiting with all matches in Dubai, Abu Dhabi and Sharjah.
The top four then progress to the semi-finals before the final in Dubai on November 14.
There is plenty at stake. A place in the next round guarantees a spot in the 2022 T20 World Cup in Australia.
There is also a financial incentive. Teams exiting at the first hurdle take home a modest $40,000.
The eventual champions pocket a $1.6 million winner's cheque.
The top nations will join the event -- played in stadiums 70-percent full -- on October 23, with Australia and South Africa meeting in the opener of the Super 12 stage and England up against West Indies.
Asian giants India will begin their campaign against arch-rivals and fellow former champions Pakistan on October 24 with Virat Kohli looking to go out with a bang before stepping down as captain of the T20 side.
Pakistan have won their last 10 Twenty20 internationals in the UAE and captain Babar Azam claimed Saturday that run will give his men the edge over India next weekend.
However, they have an abysmal record against India having lost all five times they have met at the T20 World Cup.