A controversial try helped Northern Bulls to a bonus-point 35-18 win over Otago Highlanders Saturday and second place in the Super 15 standings. Centre JJ Engelbrecht appeared to pass forward to wing Akona Ndungane, who darted clear from deep in his own half to score. Fly-half Morne Steyn converted to give the South Africans a 23-6 half-time lead and left the New Zealanders with too steep a hill to climb. The South African television match official (TMO) gave the nod to Ndungane after watching numerous replays of the Engelbrecht pass. He seemed to blunder again nine minutes after half-time when he disallowed a try by Bulls centre Jan Serfontein, believing there was a double movement. However, big-screen replays showed Serfontein being grounded just short of the try-line and then stretching his hand to dot the ball down. The TMO was not the only person having a challenging time as referee Jaco Peyper awarded many penalties and two yellow cards to Highlanders in an error-strewn encounter. While a Bulls victory was never in doubt after Ndungane touched down before a 22,000 crowd, the three-time champions left it late to claim the bonus-point fourth try. Only two minutes remained when replacement scrum-half Jano Vermaak burst away from a driving maul and dived over in the corner for the only try Steyn failed to convert. Steyn succeeded with six of eight shots at goal -- three conversions and three penalties -- to draw level with Gareth Anscombe of Waikato Chiefs on 163 points at the top of the scoring charts. Bulls captain Pierre Spies celebrated 100 Super Rugby appearances with a try, brushing aside rival No.8 Mose Tuiali'i to charge over from close range after another driving maul. Engelbrecht scored the Bulls' other try just 100 seconds into the game, grabbing a poor, long, low pass from scrum-half Francois Hougaard to go over far out. Highlanders, who won nine and drew one of 15 previous clashes against the Bulls, scored tries through Japan-born replacement scrum-half Fumiaki Tanaka and centre Tamati Ellison. Another substitute back, Hayden Parker, landed his first conversion and was deprived by the post second time round while fly-half Colin Slade slotted two first-half penalties. The result lifted Bulls one place in the combined standings, two points behind leaders and title holders Chiefs, who won at Wellington Hurricanes Friday. Highlanders' second consecutive loss in South Africa and 10th in 11 matches left them in bottom place, three points behind Western Force of Australia.