Harlequins reach Challenge Cup semis with 18-16 victory over Worcester

Replacement fly-half Demetri Catrakilis kicked a penalty three minutes from time as Quins booked a last-four clash against Clermont Auvergne or Northampton.

Centre Ben Tapuai and wing Cadan Murley scored tries for three-time Challenge Cup winners Quins, with Catrakilis landing a conversion and Marcus Smith a penalty.

Worcester posted touchdowns from wings Bryce Heem and Tom Howe, while Scotland international fly-half Duncan Weir kicked two penalties.

But Quins, who lifted the trophy in 2001, 2004 and 2011, held their nerve to win a game that saw the lead change hands four times in the second half.

Scotland flanker Cornell Du Preez was named on Worcester's bench, returning after suffering a fractured larynx in early September that saw him spend six weeks in hospital, while starting XV changes included Heem replacing rested Wales Six Nations star Josh Adams.

Quins replaced injured prop Joe Marler with Lewis Boyce, and Will Collier took over from rested England tighthead Kyle Sinckler.

Elsewhere, Jack Clifford lined up at number eight instead of Alex Dombrandt, packing down in the back-row alongside Renaldo Bothma and Chris Robshaw.

The visitors were immediately on the back foot as Worcester sought early set-piece control, and they lost lock George Merrick to injury after just six minutes, with Ben Glynn replacing him.

Quins had to absorb considerable pressure, but they showed promising counter-attacking glimpses inspired by Smith, and they stung Worcester through an impressive 17th-minute try.

Smith was involved twice in the build-up before his pass freed Murley, who finished strongly to give Quins a 5-0 lead.

Their injury woes would not abate, though, and prop Collier was forced off midway through the half before Worcester drew level.

Referee Alexandre Ruiz had already awarded them a penalty 10 metres out, but he played advantage and Warriors capitalised as Weir's pinpoint cross-kick was caught by Heem, who crossed unopposed.

Smith then nudged Quins ahead with a close-range penalty four minutes before the break, while Weir missed a long-range chance as the visitors shaded an attritional half 8-5.

Worcester showed four changes for the second period - a new front-row and Francois Venter replacing centre Ryan Mills - and it had the desired effect within seven minutes.

Scrum-half Francois Hougaard led a break out of Worcester's half, before Warriors patiently went through phase-play and full-back Chris Pennell kicked into space and Howe finished impressively.

Du Preez made a 54th-minute entry, and Weir landed his first successful kick of the night, booting a penalty that opened up a five-point advantage.

Back came Quins, though, when scrum-half Danny Care chipped over Worcester's defence and Tapuai finished off.

Catrakilis converted, and although Weir's long-range strike put Worcester back in front, Catrakilis came up trumps for Quins two minutes later and the Londoners held on.