Here, Flashscore has reflected on the year as a whole and picked out some of the biggest surprises, shocks and upsets across sport in 2023.
Ngannou sends shockwave through boxing
Former UFC heavyweight champion Francis Ngannou took the growingly popular step of going into boxing after agreeing a deal to move away from MMA.
The Cameroonian signed on to fight WBC heavyweight boxing champion Tyson Fury in the latest Saudi Arabia mega-fight - with the vast majority of supporters predicting a straightforward victory for one of the best boxers on the planet.
What followed, though, shocked the world.
Ngannou went flying into the bout and looked completely unphased by his opponent, even knocking down Fury in the third round.
The surprises didn't end there, with the MMA fighter going toe-to-toe with 'The Gypsy King' for a full 10 rounds before narrowly - and perhaps unfairly - losing via a split decision in his first-ever boxing match.
Ngannou impressed everyone with his skill and left the ring with a potentially huge future in boxing ahead of him after proving he could face up to the very best in the business.
USWNT fall short at Women's World Cup
The Women's World Cup ended with Spain toppling England 1-0 in the final which was an upset in itself, but one of the best women's teams in the world in the USA exited the tournament early to the shock of fans following the tournament.
The USWNT had won the previous two editions of the competition, triumphing in 2015 and 2019, so it was natural that supporters labelled them as one of the favourites in 2023 as well.
Their quest for a 'three-peat' was coupled with one final major tournament for the legendary Megan Rapinoe, but it all fell apart in the round of 16.
USA scraped through their group with a win against Vietnam and two unconvincing draws against the Netherlands and Portugal.
They remained lacklustre in the knockout stages and were held to a 0-0 draw by Sweden before losing on penalties - crashing out of the competition earlier than anyone expected.
Mackenzie McDonald shocks Rafael Nadal
Injuries have plagued the latter stages of Rafael Nadal's tennis career, but he was still the firm favourite heading into a second round Australian Open tie against Mackenzie McDonald.
Nadal was the top seed at the tournament and the defending champion from 2022 - having also won the French Open that year - while McDonald was ranked 65th in the world at the time.
So, naturally, the Spaniard was the clear favourite and many thought it would be a straightforward affair for the 22-time Grand Slam champion.
McDonald didn't subscribe to those views, though, and won the match in straight sets (6-4, 6-4, 7-5).
The shock victory boosted the American's ranking and reputation in tennis, while leaving an injury-hit Nadal wondering what would come next.
Unfortunately for the former champion, that was the last match he featured in and his ATP world ranking has slipped to 666.
Afghanistan deflate England's Cricket World Cup
England's cricket team have had a poor year all round, including losing the Ashes on home soil to Australia and being eliminated during the early stages of the World Cup.
Despite injuries limiting the involvement of Ben Stokes, England were still expected to comfortably beat Afghanistan in their third match of the World Cup.
The defending champions had already lost their opening game against New Zealand but bounced back with a good win against Bangladesh, leaving them in a nice position to take on Afghanistan.
What followed was a poor showing both bowling and batting, allowing their opponents to seal a famous victory - their first ever against England and what was at the time just their second ever win at a World Cup.
Afghanistan won by 69 runs after hitting 284 to England's 215, which left Brendon McCullum's side in a precarious position.
They failed to recover from the shock defeat, going on to lose their next four games and be eliminated from the competition.
Sheffield Wednesday's comeback to end all comebacks
The League One season ended with automatic promotion for Plymouth Argyle and Ipswich Town, while Sheffield Wednesday, Barnsley, Bolton and Peterborough had to settle for the play-off spots.
The Owls were by far the best of the four sides, finishing in third place on 96 points, just five away from first - and 10 ahead of Barnsley in fourth.
So, when they suffered a shock 4-0 defeat to Peterborough in first leg of their play-off semi-final, many supporters were outraged and it looked like their promotion journey was over.
In the reverse fixture, though, goals from Michael Smith, Lee Gregory, Reece James and a 98th minute equaliser from Liam Palmer took the game to extra-time.
The drama continued, with Peterborough going 5-4 up on aggregate, before Callum Patterson netted to take the game to penalties.
Wednesday would go on to win the shootout in one of the greatest play-off comebacks of all time and then come out victorious at Wembley against Barnsley, with Josh Windass scoring a 123rd minute winner to secure promotion to the Championship.
Fiji claim maiden victory against England
Ahead of the 2023 Rugby World Cup, England had lost two of three warm-up matches and things weren't looking good for Steve Borthwick's side.
They ended their warm-up fixtures by hosting a match against Fiji - who had never beaten England in their entire history.
That should have been a straightforward victory for the home side, but the Pacific Islanders spoiled the party with a superb performance and came out 30-22 victors.
Three second half tries for the Fijians was enough to see off a weak England side to the shock of supporters around the country.
England would get their revenge with a 30-24 win during the knockout stages of the World Cup, but Fiji's excellent performance at Twickenham will be remembered for years to come.
Luton complete their fairytale
Nine years ago, Luton Town were promoted from the National League (called the Conference at the time), ending a five year stretch in England's fifth tier.
Since then, the Hatters have been on a rise back up the footballing pyramid including an automatic promotion in League Two, winning League One and a Championship play-off defeat in 2021/22.
Much had been made about the clubs' unorthodox stadium and their limited budget, but that would all change in May of 2023.
Having not been in the top flight since 1992, the pressure was stacked against Luton when they made the short trip to Wembley for a play-off final against Coventry.
Rob Edwards' side had defied expectations up to that point, dealing with limited resources in comparison to the majority of Championship sides.
When the play-off final rolled around, Luton needed a penalty shootout to decide their fate, winning 6-5 after Coventry's Fankaty Dabo put his effort over the bar.
The scenes that followed represented a side who have had to deal with more adversity than most, including points deductions and their captain Tom Lockyer collapsing on the pitch during the final at Wembley, finally making it back to the big time.
