Andri Mikhnov scored a brace as Ukraine racked up their third win on the trot to stay undefeated at the 2016 IIHF Ice Hockey World Championship Division I Group B in Zagreb.

"We have a certain level that we are capable of playing at and when we stay on that level we will continue to have good results," said Ukraine's head coach Olexander Savitsky following their 7-1 win against Estonia.

Robert Rooba scored Estonia's only marker on a penalty shot. Daniil Seppenen made his full World Championship debut for Estonia in the net and recorded 28 saves.

Ukraine stormed ahead from the outset and dominated Estonia for long periods of a one-sided first frame. Despite winning the shots 23-7 their reward was only two goals thanks to inspiring goaltending by Seppenen during the first 20 minutes.

Ukraina got off the mark at 05:03 Volodymyr Aleksyuk hit a pass from defensive zone for Yevgen Tymchenko charging down the right who laid the puck on a plate for an onrushing Vladyslav Gavryk to tap home the opener.

Viktor Zakharov hit the post as Ukraine pinned down the Estonian's in their defensive zone but had to wait until 14:12 when Roman Blagy deked Aleksandr Ossipov at the blueline and raced clear to hit home a composed finish for 2-0.

"I was not at all happy with our start, and I had to raise my voice after the first period as we did not appear to be mentally or physically ready for this game," said Estonia's head coach Jussi Tupamaki.

A transformed Estonian team then stepped out on the ice for the second period, outshot Ukraine 14-5 but seemed unable to capitalize on their scoring chances. Robert Rooba missed a fine chance on a breakaway for Estonia, but soon after redeem himself as Estonia was awarded a penalty shot which he cooly slotted home to cut the deficit down to a goal.

Aleksandr Petrov, Andrei Makrov and Roman Andrejev all squandered fine chances for Estonia to draw the game level, before against the run of play, Vitali Andreikiv of Ukraine carries the puck into Estonia's zone, picked out Mikhnov in the slot for 3-1 at 36:25. Only 31 seconds later, Ukraine score again. A careless Ossipov pass behind his own net is snatched up Gavryk who feeds Tymchenko to dispatch the puck behind Seppenen to increase Ukraine's lead to 4-1.

"After our bad first period, I am quite content with how we then came out and created a lot of scoring chances against such a strong Ukrainian team, but when you play against a team of this calibre, you really need to score on your chances," said Estonia coach Tupamaki.

After Estonia's Makrov goes close to pull one back for Estonia early in the third period, tired legs and minds start to take its toll. Ukraine's Yuri Petrangovsky sails through to make it 5-1 at 44:34. Mikhnov is given ample time in front of Seppenen to score his second of the afternoon midway through the final period, before Artem Bondariev top shelf finish close the scoring at 7-1 with 4:52 to go.

With three wins out of three, Ukraine rolls on to face Lithuania on Friday, while Estonia will chase their first win facing off against Croatia.