The Rhinos batted first on Saturday and could only manage 50 runs.
Deni won the toss and elected to bat, while the temperature was still in the mid-30s.
Harry Hillier and Tom McCallum opened the batting, facing two of the most successful bowlers in the competition.
McCallum looked solid before leaving a straight one from the spinner, Jim Daniels.
Hillier nicked one off Adam DeCiccio and the Rhinos were in trouble at 2-3.
Daniels also bowled Liam Pitts.
Brodie Bennett and Brad Todd added 15 for the fourth wicket before Bennett hit one to mid off.
Dean Edge was bowled shortly after, and the Rhinos had slumped to 5-24.
Kai Hillier received a good ball from DeCiccio, taking the outside edge and was caught at point.
Todd hit a catch to mid off and Noah Sneddon held his second catch for the day.
The Rhinos were in need of lower order partnerships, hoping to post somewhere near 100.
Daniel and DeCiccio had other ideas.
Charlie Paton was undefeated again for eight while Dean MacDonald hit a couple of boundaries through mid wicket before being bowled for nine.
Only two batters, Brodie Bennett (14) and Brad Todd (10), could manage double figures.
It was a disappointing day for the Rhinos.
Deni then had to bowl 59 overs to complete day one.
The Cobram team batted well in the hot conditions and finished the day’s play at 4-199 - a first innings lead of 149 with six wickets in hand.
The Cobram captain Adam DeCiccio is 49 not out while Lachlan Hyde could be eyeing a century on 69 not out at the end of the day.
Bennett was the pick of the bowlers with his marathon 16 over opening spell.
He had 2-25, including six maidens. Five were bowled consecutively.
While great, Bennett was desperately unlucky beating the bat on many occasions.
Evan Pocock bowled well, his wicket being a sharp caught and bowled chance.
Pocock’s figures were 1-54 off 15 overs.
Lochie Holloway was the other successful bowler, spinning one past Tyron Baden (32).
MacDonald was sharp behind the stumps and completed the stumping.
The Rhinos face a tough task next week with a couple of possible scenarios.
Cobram may look to add some quick runs and then put the Rhinos back in, looking for the outright victory.
Cobram are clear on top of the ladder so may look for some valuable batting practice instead.
Either way, the Rhinos will aim for a better batting performance in the second innings.