2017 saw its fair share of unlikely sporting wins, so we've taken a look back at some of the surprising victories over the last 12 months.
Sloane Stephens' US Open win
Ranked number 83 heading into the tournament, the 24-year-old powered her way through the early rounds before meeting Venus Williams in the semi-final.
Stephens easily won the the first set 6-1 and almost broke Williams early in the second, only for the seven-time Grand Slam winner to rally and take the set 6-0.
The third and deciding set was a 73-minute epic which ebbed and flowed before Stephens eventually won 7-5.
In the final, she beat her compatriot Madison Keys 6-3, 6-0 to wrap up her first Grand Slam win in little over an hour. She also became the first American woman not named Williams to win a Grand Slam title since 2002.
Her post-match interview also made waves, as she was refreshingly honest and funny as she spoke about her win.
The Patriots Super Bowl comeback win
Claiming any Patriots win as unlikely would normally be untrue. However, the manner of their comeback against the Atlanta Falcons in the biggest game of the season is worthy of mention.
The New England outfit trailed by 25 points at one stage - only for legendary quarter-back Tom Brady to rally his side and take the game to overtime.
The Patriots overcame the largest deficit in Super Bowl history while Brady set a record for Super Bowl passing yards - before the overtime period.
In the end, the Patriots won 34-28 after James White broke the plane from close range, consigning the Falcons to a historic defeat.
Barcelona's comeback win over PSG
Trailing 4-0 from the first leg against big-spending Paris Saint-Germain on St. Valetine's day, the Catalan giants rallied in the Camp Nou.
Three goals in the first hour gave the home side hope that what seemed impossible was now quite probable.
Barcelona players celebrate. Picture by: NurPhoto/SIPA USA/PA Images
However, an Edison Cavani half-volley looked to have settled the tie, with Barca now needing to score three more to advance.
Step forward Neymar, who scored a magnificent free-kick before Luis Suarez was awarded a dubious penalty which Neymar subsequently converted.
The dramatic comeback was complete in the dying seconds, when Sergio Roberto volleyed into the net after a beautifully floated ball from the Brazilian, sparking scenes of unrefined joy, including in the commentary box.
Houston Astros' World Series win
The Astros have been waiting a long time to claim their first World Series title, and looked as though they were nowhere near one when a writer with Sports Illustrated predicted back in 2014 that the franchise would win it just three years later.
Ben Reiter was given access to the team's long term strategy and data analytics, which they had hoped would give them marginal gains over their competitors in the years ahead.
One of the 'losingest' teams in baseball managed to turn their whole side around in the intervening years, and in the end, the last laugh went to the former laughing stock of the league.
Rose Namajunas beats Johanna Jedrzejczyk
Namajunas handed her Polish rival her first ever professional defeat and dethroned her as the UFC's women's straw-weight champion.
Jedrzejczyk ruled the division with ruthless efficiency since beating Carla Esparza in March 2015. She had defended the title five times - landing over 100 strikes in each bout.
Namajunas stunned her rival early on - taking the fight to her from the off and stopping her in the first round.