Martinez came on as 70th minute substitute but wasted no time scoring against Newcastle who remain second in the Championship table. League One Oxford remain in fourteenth spot in their league table one division below the Magpies.
Oxford signed the former Spain under-17 international Martinez on a season long loan from West Ham earlier this month. The Hammers paid £2.4m last April for the 19-year-old striker after he scored more than 100 goals for Valencia’s youth teams.
At the time of the loan Martinez said “I’m very happy to sign for Oxford.
“My objective is to play as many games as possible and score goals to help the team.
“It’s a challenge to go and play in League One, learn English football and score as many goals as possible.”
Goal: Martinez #oufc 3-0 Newcastle pic.twitter.com/YgHXjt0yaz
— BBC Oxford Sport (@bbcoxfordsport) January 28, 2017