There were few items left to tick on Bill Shankly's Liverpool to-do list by May 23, 1973.

The Scot’s top-to-bottom transformation at Anfield across the preceding 13-and-a-half years had included returning the Reds to the First Division, winning the top flight three times and ending the club’s FA Cup hoodoo by securing a cherished first success at Wembley in 1965.

One objective had eluded Shankly’s great sides, however: European glory.

There had been near-misses, with a controversial semi-final exit against Internazionale in the 1964-65 European Cup followed by a defeat at the last hurdle of the Cup Winners’ Cup versus Borussia Dortmund a season later.

But on this day 50 years ago, Liverpool’s wait to conquer Europe ended.

They had to do it the hard way, though.

At the halfway point of their two-legged UEFA Cup final versus German greats Borussia Monchengladbach, Shankly’s boys led handsomely, having chalked up a 3-0 Anfield win in match one.

Kick-off of the tie in L4 had been delayed 24 hours by a waterlogged pitch and the additional thinking time that afforded the manager proved highly influential on the outcome.

Shankly altered his original starting line-up to include John Toshack and was rewarded by the Welshman teeing up a pair of first-half goals for strike partner Kevin Keegan.

That double from the No.7 sandwiched a Keegan penalty that was saved by Wolfgang Kleff and at the other end Dietmar Danner hit the post for Gladbach.

Larry Lloyd’s header extended Liverpool’s lead to three just after the hour mark, though they needed Ray Clemence to produce an excellent save in pushing away a spot-kick from Jupp Heynckes in front of a swaying Kop.

“I watched Heynckes take a penalty in the semi-final on television and decided to dive the same way. The save was a reward for my homework,” said Clemence of an intervention that crucially denied the visitors an away goal.

“Liverpool home – and dry” splashed The Guardian’s post-match headline, nodding to the delay of the fixture with phrasing that equally captured the expectancy the Reds would now go on to comfortably complete the job.

Thirteen days later, on May 23, they reconvened at Bokelbergstadion – but confirming Liverpool’s first ever European trophy proved anything other than a formality.

The teams emerge for the decisive UEFA Cup final second leg on this day in 1973

Outplayed and overpowered by a Gladbach team energised by their own crowd, Shankly’s side’s aggregate advantage had been reduced to just one before half-time.

Heynckes made amends for his penalty miss at Anfield with a close-range finish to open the scoring for the hosts and swiftly netted another with a beautiful, curling effort into the top right corner from 14 yards.

The Reds were having to consider an unthinkable humbling and the cup remaining in Germany, yet found the resolve to hold at bay heavy pressure and preserve their now-slender lead in the tie.

As time ticked away – slowly, slowly for Kopites – Gladbach legs showed signs of weariness and their attacks faded, with Liverpool carving out several of their own opportunities in the closing stages though unable to take one that would fully put the game to bed.

But 0-2 on the night proved enough for 3-2 overall and Shankly had completed another mission: the First Division champions hoisted aloft the first piece of European silverware in LFC history.