Deanne Smalley gave Oxford United the lead in the 25th minute before trialist Adam McGurk fired Blues level just before the break.
McGurk could have won it for the visitors at the death only to see his accurate header brilliantly tipped wide by 'keeper Ryan Clarke.
Tom Adeyemi recovered from a hamstring injury to make his first appearance in a Blues shirt while Scott Allan, who joined on a season-long loan from West Bromwich Albion on Friday, played almost an hour. As well as McGurk, fellow trialists Mark Little, a right-back, and Liam Davis, a left-sider, entered the fray at the break.
In a fixture that lacked goalmouth action, Lee Clark will have been disappointed with the manner his side fell behind. On the break, Smalley muscled his way into the left side of the Blues box and found himself with only Colin Doyle to beat which he duly did at the near post.
However Blues didn't head into the break a goal down as McGurk's equaliser arrived in the 43rd minute. From the left, Mitch Hancox picked out McGurk who had found a pocket of space and he rifled home a fine finish from eight yards.
There was little action to report in the second-half but McGurk could have capped a fine performance with a winning goal at the death. Davis' cross from the left found the rising head of the former Northern Ireland U21 international only for the effort to be brilliantly kept out by a full-stretch Clarke.
Blues XI: Doyle; Bartley (Higgins 71), Mullins, Burn; Eardley (Little H/T), Reilly, Allan (Arthur 58), Adeyemi (Lee 58), Hancox (Davis H/T); McGurk, Green (Shinnie 67). Subs: Randolph, Elliott, Burke, Robinson.
Oxford United XI: Clarke; Newey, Raynes (Heath H/T), Wright (C), Rigg (Meades 67), Constable (Kitson H/T), Smalley (Potter H/T), Whing (Marsh 77), Rose (O'Dowda 77), Davies (Hall 67), Bevans. Subs: Crocombe.