Mikael Mandron and Owen Dale were on target as Crewe made it back-to-back Sky Bet League One victories as they followed up their impressive win over Peterborough by beating Oxford 2-0 at the Kassam Stadium.
This was a third attempt to play this League One match after two previous fixtures were scuppered by Covid-19 cases in the Crewe camp.
After a tepid opening, Alex showed the more attacking menace and Tom Lowery fired an effort from 20 yards just wide.
Mandron got the breakthrough after 28 minutes as he turned in Oli Finney's left-wing cross from a tight angle.
He should have had a second as he capitalised on indecision by Elliott Moore to break clear, only to sky his shot.
Oxford improved in the second half and Sam Winnall squandered two opportunities to equalise from free headers.
Crewe nearly doubled their lead as Simon Eastwood saved from Omar Beckles and Mandron's follow-up was blocked on the line by James Henry.
But substitute Dale sealed the points in stoppage time, drilling a low shot into the bottom corner to see Crewe move up to 12th as the hosts sit one point from safety.