Serena Williams crashes out of Wimbledon after shock meltdown

Serena Williams' long-awaited grand slam return has ended in heartbreak after the American crashed out in a rollercoaster first round clash at Wimbledon.

The 23-time grand slam champion - playing in her first slam since last year's Wimbledon tournament where she hobbled out of the first round with injury - went down to France's Harmony Tan 7-5 1-6 7-6 (10/7).

'SHOULD BE BANNED': Nick Kyrgios' 'disgusting' act stuns Wimbledon

'NO WORDS': Tennis fans shattered over Cilic and Berrettini news

Williams squandered a 4-0 lead in the third set tiebreak, before bowing out at the All England Club in the most dramatic of fashions.

The 40-year-old Williams ended a 12-month hiatus from tennis to team with Ons Jabeur in last week's Eastbourne doubles, in a positive tune-up for her tilt at a 24th grand slam title at the All England Club.

Seven-time Wimbledon singles queen Williams has not won a grand slam since 2017's Australian Open, and has lost two finals at SW19 during the drought, to Angelique Kerber in 2018 and Halep in 2019.

Tan, the unheralded 24-year-old French woman edged a gripping first set before Williams roared back into contention in style to send the match into a deciding third set.

After more than two hours of thrilling tennis, very little could separate the players as the third set edged closer to a tiebreak.

However, Williams erupted late in the third set after converting a break point opportunity to go up 5-4 and have a chance to serve for the match.

Despite the American's 23 grand slams, nerves still appeared to play a major part in the 40-year-old's inability to serve out the match as her tentative ground strokes allowed Tan to break right back.

The French woman held her own nerves to stretch Williams all over the court, showing guile and craft that belied her underdog status.

Tan eventually went 6-5 up to heap the pressure firmly back on Williams, who had to hold her own serve to force a tiebreak in the decider.

The American found herself match point down when she put an errant backhand smash long, but kept herself alive the very next point after burying a forehand smash at the net.

Williams had the crowd off their feet after digging deep into her reserves to claim the next two points and set up a tiebreak.

Tennis world in disbelief over Serena Williams drama

The seven-time Wimbledon champion looked destined to be heading to the second round when she raced out to a 4-0 lead.

However, Tan turned things around in stunning fashion with a number of expertly crafted points to get herself back in the contest.

Serena stemmed the bleeding to win a couple of massive points in succession, before Tan once again took the ascendancy to edge closer to victory.

The American pulled one point back to give herself a slim chance but Tan shut the door on any comeback after clinching back-to-back points to clinch an extraordinary victory.

The crazy scenes left the tennis world in a frenzy on social media.

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.