Cardiff City, only six points above the relegation zone in the EFL Championship, made Villa work hard but Asensio, on loan from PSG, followed up last Saturday’s goals in the win over Chelsea with another pair here.
Villa could have been forgiven for rotating more, considering they return to Champions League action in Bruges next week, but Asensio and Rashford were among the five changes made in a very attacking selection.
Rashford’s best contribution of the first half came two minutes before the break when he nodded Ian Maatsen’s header on for Watkins who, stealing in on the blindside, saw his close-range volley saved by Horvath.
Tielemans spotted Rashford’s run and lofted his pass into the left channel perfectly for the England striker to square his pass first time for his fellow loanee to hit home on the half volley.
Two more goals from Marco Asensio enabled Aston Villa to reach the last eight of the FA Cup for the first time since they made it to the final in 2015.
